become vain (Greek #3154)

Romans
1:21   *
ho (Greek #3588)
the definite article; the (sometimes to be supplied, at others omitted, in English idiom)
KJV usage: the, this, that, one, he, she, it, etc.
Pronounce: ho
Origin: ἡ (hay), and the neuter τό (to) in all their inflections
Because that
dioti (Greek #1360)
on the very account that, or inasmuch as
KJV usage: because (that), for, therefore.
Pronounce: dee-ot'-ee
Origin: from 1223 and 3754
, when they knew
ginosko (Greek #1097)
to "know" (absolutely) in a great variety of applications and with many implications (as follow, with others not thus clearly expressed)
KJV usage: allow, be aware (of), feel, (have) know(-ledge), perceived, be resolved, can speak, be sure, understand.
Pronounce: ghin-oce'-ko
Origin: a prolonged form of a primary verb
God
ho (Greek #3588)
the definite article; the (sometimes to be supplied, at others omitted, in English idiom)
KJV usage: the, this, that, one, he, she, it, etc.
Pronounce: ho
Origin: ἡ (hay), and the neuter τό (to) in all their inflections
theos (Greek #2316)
a deity, especially (with 3588) the supreme Divinity; figuratively, a magistrate; by Hebraism, very
KJV usage: X exceeding, God, god(-ly, -ward).
Pronounce: theh'-os
Origin: of uncertain affinity
, they glorified
doxazo (Greek #1392)
to render (or esteem) glorious (in a wide application)
KJV usage: (make) glorify(-ious), full of (have) glory, honour, magnify.
Pronounce: dox-ad'-zo
Origin: from 1391
him not
ou (Greek #3756)
the absolute negative (compare 3361) adverb; no or not
KJV usage: + long, nay, neither, never, no (X man), none, (can-)not, + nothing, + special, un(-worthy), when, + without, + yet but. See also 3364, 3372.
Pronounce: oo
Origin: οὐκ (ook), and (before an aspirate) οὐχ (ookh) a primary word
as
hos (Greek #5613)
which how, i.e. in that manner (very variously used, as follows)
KJV usage: about, after (that), (according) as (it had been, it were), as soon (as), even as (like), for, how (greatly), like (as, unto), since, so (that), that, to wit, unto, when(-soever), while, X with all speed.
Pronounce: hoce
Origin: probably adverb of comparative from 3739
God
theos (Greek #2316)
a deity, especially (with 3588) the supreme Divinity; figuratively, a magistrate; by Hebraism, very
KJV usage: X exceeding, God, god(-ly, -ward).
Pronounce: theh'-os
Origin: of uncertain affinity
, neither
e (Greek #2228)
disjunctive, or; comparative, than
KJV usage: and, but (either), (n-)either, except it be, (n-)or (else), rather, save, than, that, what, yea. Often used in connection with other particles. Compare especially 2235, 2260, 2273.
Pronounce: ay
Origin: a primary particle of distinction between two connected terms
were thankful
eucharisteo (Greek #2168)
to be grateful, i.e. (actively) to express gratitude (towards); specially, to say grace at a meal
KJV usage: (give) thank(-ful, -s).
Pronounce: yoo-khar-is-teh'-o
Origin: from 2170
; but
alla (Greek #235)
properly, other things, i.e. (adverbially) contrariwise (in many relations)
KJV usage: and, but (even), howbeit, indeed, nay, nevertheless, no, notwithstanding, save, therefore, yea, yet.
Pronounce: al-lah'
Origin: neuter plural of 243
became vain
mataioo (Greek #3154)
to render (passively, become) foolish, i.e. (morally) wicked or (specially), idolatrous
KJV usage: become vain.
Pronounce: mat-ah-yo'-o
Origin: from 3152
in
en (Greek #1722)
"in," at, (up-)on, by, etc.
KJV usage: about, after, against, + almost, X altogether, among, X as, at, before, between, (here-)by (+ all means), for (... sake of), + give self wholly to, (here-)in(-to, -wardly), X mightily, (because) of, (up-)on, (open-)ly, X outwardly, one, X quickly, X shortly, (speedi-)ly, X that, X there(-in, -on), through(-out), (un-)to(-ward), under, when, where(-with), while, with(-in). Often used in compounds, with substantially the same import; rarely with verbs of motion, and then not to indicate direction, except (elliptically) by a separate (and different) preposition.
Pronounce: en
Origin: a primary preposition denoting (fixed) position (in place, time or state), and (by implication) instrumentality (medially or constructively), i.e. a relation of rest (intermediate between 1519 and 1537)
their
autos (Greek #846)
the reflexive pronoun self, used (alone or in the comparative 1438) of the third person , and (with the proper personal pronoun) of the other persons
KJV usage: her, it(-self), one, the other, (mine) own, said, (self-), the) same, ((him-, my-, thy- )self, (your-)selves, she, that, their(-s), them(-selves), there(-at, - by, -in, -into, -of, -on, -with), they, (these) things, this (man), those, together, very, which. Compare 848.
Pronounce: ow-tos'
Origin: from the particle αὖ (perhaps akin to the base of 109 through the idea of a baffling wind) (backward)
imaginations
ho (Greek #3588)
the definite article; the (sometimes to be supplied, at others omitted, in English idiom)
KJV usage: the, this, that, one, he, she, it, etc.
Pronounce: ho
Origin: ἡ (hay), and the neuter τό (to) in all their inflections
dialogismos (Greek #1261)
discussion, i.e. (internal) consideration (by implication, purpose), or (external) debate
KJV usage: dispute, doubtful(-ing), imagination, reasoning, thought.
Pronounce: dee-al-og-is-mos'
Origin: from 1260
, and
kai (Greek #2532)
and, also, even, so then, too, etc.; often used in connection (or composition) with other particles or small words
KJV usage: and, also, both, but, even, for, if, or, so, that, then, therefore, when, yet.
Pronounce: kahee
Origin: apparently, a primary particle, having a copulative and sometimes also a cumulative force
their
autos (Greek #846)
the reflexive pronoun self, used (alone or in the comparative 1438) of the third person , and (with the proper personal pronoun) of the other persons
KJV usage: her, it(-self), one, the other, (mine) own, said, (self-), the) same, ((him-, my-, thy- )self, (your-)selves, she, that, their(-s), them(-selves), there(-at, - by, -in, -into, -of, -on, -with), they, (these) things, this (man), those, together, very, which. Compare 848.
Pronounce: ow-tos'
Origin: from the particle αὖ (perhaps akin to the base of 109 through the idea of a baffling wind) (backward)
foolish
asunetos (Greek #801)
unintelligent; by implication, wicked
KJV usage: foolish, without understanding.
Pronounce: as-oon'-ay-tos
Origin: from 1 (as a negative particle) and 4908
heart
kardia (Greek #2588)
the heart, i.e. (figuratively) the thoughts or feelings (mind); also (by analogy) the middle
KJV usage: (+ broken-)heart(-ed).
Pronounce: kar-dee'-ah
Origin: prolonged from a primary κάρ (Latin cor, "heart")
was darkened
skotizo (Greek #4654)
to obscure (literally or figuratively)
KJV usage: darken.
Pronounce: skot-id-zo
Origin: from 4655
.