Quick Definition
ἄπταιστος, ον Adj without stumbling or falling
Strong's Definition
from 1 (as a negative particle) and a derivative of 4417; not stumbling, i.e. (figuratively) without sin
KJV Usage: from falling
UBS Dictionary of the Greek New Testament
adjc. | -ον | ἀ- + πταίω
88.292 · Moral and Ethical Qualities and Related Behavior · Sin, Wrongdoing, Guilt
free from stumbling, free from sinning pertaining to not having failed to keep the law (of God)
UBS Dictionary of the Greek New Testament © United Bible Societies, licensed CC BY-SA 4.0.
Thayer's Greek Lexicon
ἄπταιστος, -ov (Taio, q. v-), not stumbling, standing Jirm, exempt from falling, (prop., of a horse, Xen. de re eq. 1,6); metaph.: Jude 24. [Cf. W. 97 (92); B. 42 (37).]
Mounce Concise Greek Dictionary
ἄπταιστος aptaistos 1x
free from stumbling; met. free from moral stumbling, offence; irreprehensible, Jude 24*
Abbott-Smith Greek Lexicon
** ἄ-πταιστος, -ον
(< πταίω), [in LXX: III Mac 6:39*;]
without stumbling, sure-footed: metaph. (MM, s.v.), Ju 24.†
Moulton & Milligan — Vocabulary of the Greek NT
ἄπταιστος. In the lack of other citations this NT ἅπ. elp. (Jude *4) may be illustrated from M. Aur. ν. 9 τὸ ἄπταιστον Kal εὔρουν ἐν πᾶσι, ‘the security and happy course of all things,” which depend on the faculty of understanding and knowledge. See also 3 Macc 659 6 τῶν πάντων δυνάστης ἀπταίστους αὐτοὺς ἐρρύσατο ὁμοθυμαδόν.
Liddell-Scott-Jones — Greek-English Lexicon
ἄπταιστος (aptaistos) — without falling. ἄπταιστος, ον, not stumbling, ἀπταιστστερον παρέχειν τὸν ἵππον make a horse less aptto stumble, [Refs 5th c.BC+]; infallible, [Refs 2nd c.AD+]. adverb -τως[Refs 5th c.BC+]; inevitably, [Refs 2nd c.AD+]: comparative -ότερον with greater precision, [Refs 2nd c.AD+]:—also ἀπρο-τί, [Refs 2nd c.AD+]
2. intact, [Refs 1st c.AD+]
II. not causing to stumble, giving a good footing, λεία καὶ ἄ. ὁδός[Refs 1st c.BC+]