pp1a06 veritas
Meaning A true idea agrees (convenit) with its object (cum suo ideato). The object is what the idea is about. It can be either an extended thing or another idea.
A Adequate ideas: The truth (veritas) of an adequate idea is caused by the idea itself (internally)
B Inadequate ideas: An inadequate idea can (by a stroke of luck during its imagination) be entirely true, but such truth is caused externally, and cannot be known certainly.
C False ideas: A false idea is, in Ethica, actually a shorthand for a mind holding an idea not agreeing with its object (ideato) while not holding another, second, idea, namely an adequate idea implying that it indeed it does not agree. By this meaning of falsity, falsity always occurs by accident, namely by something, being absent, or lacking, that is external to the idea. Consequently, all ideas are OK in themselves, they just need to be given their adequate place in the order and connection of ideas in the mind. We never have ideas to get rid off, perfection of the mind is only a matter of adding, never of "erasing" ideas (more below).
Definitions in Ethica claim veritas (to be true definitions - even adequate). Ethica's concept of definition radically differs from the modern geometric concept, which is introducing short strings to replace long strings in order to reduce text size and readability, and where a definiendum can be eliminated out whenever desired: in Ethica, definitions are wordings of ideas, hence claim veritas (more below).
Subsets (kinds) Aeterna veritas.
Mantras [what is] vere concipere
vere percipere
necessario vera
boni et mali cognitione
Occurrence [geomap] Densely in 2p43s
NOT linked: "vero" used pleonastic ("vere intelligimus"), non vero ("really not"), simply emphasising something ("vero transiens"), and colloquial as in vera potentia ("true power"), related to pp1a03 necessarius (pleonastic) and  absolute (pleonastic) (see absolute under NOT linked), "Verum,  ... " as a sharp call of the reader's attention at the start of a statement.
{1a06 idea convenire}                                                                       ...  first occurrence of veritas  ...
 ... A true idea must correspond with its ideate or object.  ... Idea vera debet cum suo ideato convenire.
1p08s2 modificationum non existentium                                 ... about definitions: a true definition of a thing expresses its nature ...
 ... The true definition of a thing neither involves nor expresses anything beyond the nature of the thing defined ...  No definition implies or expresses a certain number of individuals, inasmuch as it expresses nothing beyond the nature of the thing defined. For instance, the definition of a triangle expresses nothing beyond the actual nature of a triangle: it does not imply any fixed number of triangles ... .  ...  veram uniuscujusque rei definitionem nihil involvere neque exprimere praeter rei definitae naturam ... nempe nullam definitionem certum aliquem numerum individuorum involvere neque exprimere quandoquidem nihil aliud exprimit quam naturam rei definit. Exempli gratia definitio trianguli nihil aliud exprimit quam simplicem naturam trianguli; at non certum aliquem triangulorum numerum ...
{1p12 substanti dividi}                                                                        ... "truly"is NOT pleonastic here: concipere can logically lead to a false, inadequate idea ...
 ... can be truly conceived  ...  ...  potest vere concipi ...
{1p20c1 aeternam veritatem}                                                         ... aeterna veritas ...  
 ... God's existence, like his essence, is an eternal truth.  ...  Dei existentiam sicut ejus essentiam aeternam esse veritatem.
2p17s Videmus itaque non sunt veluti praesentia               ...  there can never be something faulty in an imaginatio  in itself  ...
  ...  to retain the usual phraseology, the modifications [Lat: affectiones] of the human body, of which the ideas represent external bodies as present to us, we will call the images of things, though they do not recall the figure of things. When the mind regards bodies in this fashion, we say that it imagines. I will here draw attention to the fact, in order to indicate where error lies, that the imaginations of the mind, looked at in themselves, do not contain error. The mind does not err in the mere act of imagining, but only in so far as it is regarded as being without the idea, which excludes the existence of such things as it imagines to be present to it. If the mind, while imagining non-existent things as present to it, is at the same time conscious that they do not really exist, this power of imagination must be set down to the efficacy of its nature, and not to a fault  ...  ...  ut verba usitata retineamus, corporis humani affectiones quarum ideae corpora externa velut nobis praesentia repraesentant, rerum imagines vocabimus tametsi rerum figuras non referunt. Et cum mens hac ratione contemplatur corpora, eandem imaginari dicemus. Atque hic ut quid sit error indicare incipiam, notetis velim mentis imaginationes in se spectatas nihil erroris continere sive mentem ex eo quod imaginatur, non errare sed tantum quatenus consideratur carere idea quae existentiam illarum rerum quas sibi praesentes imaginatur, secludat. Nam si mens dum res non existentes ut sibi praesentes imaginatur, simul sciret res illas revera non existere, hanc sane imaginandi potentiam virtuti suae naturae  ...
{2p32 deae Deum referuntur verae}                                            ... when God = natura-sense 2 = substance has the idea of a human mind having an inadequate idea, God's idea about it is adequate ... (but N.B. God has the adequate idea about all inadaequatio actually existing and the adequate causes thereof) ...
 ... All ideas, in so far as they are referred to God, are true.  ... Omnes ideae quatenus ad Deum referuntur, verae sunt.
 ... All ideas which are in God agree in every respect with their objects ...  ... Omnes enim ideae quae in Deo sunt, cum suis ideatis omnino conveniunt ...
{2p33 Nihil positivum falsae}                                                         ... more about this in appended table below ...
 ... There is nothing positive in ideas, which causes them to be called false.  ... Nihil in ideis positivum est propter quod falsae dicuntur.
Proof.-If this be denied, conceive, if possible, a positive mode of thinking, which should constitute the distinctive quality of falsehood. Such a mode of thinking cannot be in God (II. xxxii.); external to God it cannot be or be conceived (I. xv.). Therefore there is nothing positive in ideas which causes them to be called false. Q.E.D. DEMONSTRATIO: Si negas, concipe si fieri potest, modum positivum cogitandi qui formam erroris sive [mng-eqv]  falsitatis constituat. Hic cogitandi modus non potest esse in Deo (per propositionem praecedentem {2p32}); extra Deum autem etiam nec esse nec concipi potest (per propositionem 15 partis I {1p15}). Atque adeo nihil potest dari positivum in ideis propter quod falsae dicuntur. Q.E.D.
{2p34 absoluta sive adaequata et perfecta vera}                   ... the reverse of the proposition below does not hold ...
 ... Every idea, which in us is absolute or adequate and perfect, is true.  ... Omnis idea quae in nobis est absoluta sive [prf-eqv]  adaequata et [prf-eqv] perfecta, vera est.
{2p35 Falsitas consistit privatione}                                               ... falsity is the absence of some relevant adequate ideas in the mind ...
 ... Falsity consists in the privation of knowledge, which inadequate, fragmentary, or confused ideas involve.  ... Falsitas consistit in cognitionis privatione quam ideae inadaequatae sive [mng-eqv]  mutilatae et confusae involvunt.
{2p41 primi generis falsitatis, secundi tertii vera}                ... first kind (imaginatio) can (though does not necessarily - you can be "lucky") produce false ideas, with other kinds this is - by their meanings - impossible ...
 ... Knowledge of the first kind is the only source of falsity, knowledge of the second and third kinds is necessarily true.   ... Cognitio primi generis unica est falsitatis causa, secundi autem et tertii est necessario vera.
{2p41 primi generis falsitatis, secundi tertii vera}                ... falsitas can only be produced by the first kind of knowledge (imaginatio) ... but  it can (by sheer luck) produce idea vera as well, hence the distinctive quality of the second and third kind is not vera but necessario vera ...
 ... Knowledge of the first kind is the only source of falsity, knowledge of the second and third kinds is necessarily true.  ...  Cognitio primi generis unica est falsitatis causa, secundi autem et tertii est necessario vera.
 ... To knowledge of the first kind we have  ... assigned all those ideas, which are inadequate and confused; therefore this kind of knowledge is the only source of falsity ... . Furthermore, we assigned to the second and third kinds of knowledge those ideas which are adequate; therefore these kinds are necessarily true ...  ... Ad primi generis cognitionem illas omnes ideas  ...  pertinere quae sunt inadaequatae et confusae atque adeo  ...  haec cognitio unica est falsitatis causa. Deinde ad cognitionem secundi et tertii illas pertinere diximus quae sunt adaequatae adeoque  ...  est necessario vera ...
{2p44 natura rationis necessarias}                                                ... res vere percipere explained referring to {2p41}, {1a06} and {1p29} ...
 ... It is in the nature of reason to perceive things truly (II. xli.), namely (I. Ax. vi.), as they are in themselves-that is (I. xxix.), not as contingent, but as necessary ...  ... De natura rationis est res vere percipere (per propositionem 41 hujus {2p41}) nempe (per axioma 6 partis I {1a06}) ut in se sunt hoc est (per propositionem 29 partis I {1p29}) non ut contingentes sed ut necessarias ...
{2p44c2 aeternitatis specie}                                                            ... "truly perceiving" means: as it is in itself ...  ...
 ...  Reason perceives this necessity of things  ...  truly-that is (I. Ax. vi.), as it is in itself ...  ... Hanc autem rerum necessitatem ...  vere hoc est (per axioma 6 partis I {1a06}) ut in se est, percipit ...
{3p58 affectus dantur agimus}                                                        ... [non-excl non-exh] , because inadequate, (accidentally) true ideas can be produced by imaginatio..
 ... a true or adequate idea ...  ...  veram sive [non-excl non-exh] adaequatam ideam concipit  ...

Appendix {2p33 Nihil positivum falsae} (light grey sub-table spans the space of logical possibilities)

  Existence of idea
(in attribute of thought)
existence of res ideatum
(in attribute of exension)
when in God = natura-sense 2 = substance
when in the mind
(by def.
in the mind)
evaluation of {2p33 Nihil positivum falsae}
1 YES YES YES idea vera idea vera idea adaequata or result of "lucky" imaginatio inapplicable
2 YES YES NO impossible Void Void Void by decomposition of ideas in their constituent ideas (ci's), then move to
row 1 ci's with       existing ideatum
 row 3 ci's with non-existing ideatum
3 YES NO inapplicable impossible idea falsa idea inadaequata, surely imaginatio incompleteness by {2p33 Nihil positivum falsae}
4 NO YES inapplicable impossible no idea in the mind no idea
in the mind
5 NO NO inapplicable impossible no idea in the mind no idea
in the mind

Equivalence claims involving veritas, falsitas
{2d04} [notes] 1. adequate idea 2. an idea which, in so far as it is considered in itself, without relation to the object, has all the properties or intrinsic marks of a true idea. 1. [ideam] adaequatam 2. [ideam] quae quatenus in se sine relatione ad objectum consideratur, omnes verae ideae proprietates sive [mng eqv]  denominationes intrinsecas habet.
{4p53} [About emotions] 1. [orginating] from true contemplation 2. originating [from] reason  [De affectibus] 1. ex vera contemplatione [oritur] 2. [ex] ratione oritur