Quick Definition
an indivisible part of time, a moment
Strong's Definition
uncut, i.e. (by implication) indivisible (an "atom" of time)
Derivation: from G1 (Α) (as a negative particle) and the base of G5114 (τομώτερος);
KJV Usage: moment
Thayer's Greek Lexicon
ἄτομος, ἀτομον (τέμνω to cut), that cannot be cut in two or divided, indivisible (Plato, Sophocles 229 d.; of time, Aristotle, phys. 8, 8, p. 263b, 27): ἐν ἀτόμῳ in a moment, 1Co_15:52.
Mounce Concise Greek Dictionary
ἄτομος atomos 1x
indivisible, and by impl. exceedingly minute; ἐν ἀτόμῳ , i.e. χρόνῳ , in an indivisible point of time, in an instant or moment, 1Co_15:52
Abbott-Smith Greek Lexicon
** ἄ -τομος , -ον
( < τέμνω ),
[in Sm .: Isa_54:8 ( MM , s.v. ) * ;]
indivisible; of time, ἄτομον , a moment: ἐν ἄ ., 1Co_15:52 .†
Moulton & Milligan — Vocabulary of the Greek NT
ἄτομος [page 90]
With ἐν ἀτόμῳ ( 1Co_15:52 ) cf. Symm. Isa_54:8 ἐν ἀτόμῳ ὀργῆς , where the LXX has ἐν μικρῷ θυμῷ . This will suffice to make Paul s dependence for the word on Plato and Aristotle less assured than it might have been.
Liddell-Scott — Intermediate Greek Lexicon
ἄτομος [Etym: τέμνω] "uncut, unmown", Soph. "that cannot be cut, indivisible", Plat. ; ἐν ἀτόμωι in a "moment", NTest.
STEPBible — Tyndale Abridged Greek Lexicon
ἄ-τομος, -ον
(τέμνω), [in Sm.: Isa.54:8 (MM, see word) * ;]
indivisible; of time, ἄτομον, a moment: ἐν ἄ., 1Co.15:52.†
(AS)