Quick Definition
ἄκαρπος, ον Adj unfruitful, barren
Strong's Definition
from 1 (as a negative particle) and 2590; barren (literally or figuratively)
KJV Usage: without fruit, unfruitful
UBS Dictionary of the Greek New Testament
adjc. | -ον | ἀ- + καρπός
23.202 · Physiological Processes and States · Ripen, Produce Fruit, Bear Seed
without fruit, bearing no fruit, producing no harvest pertaining to not producing seed, fruit, or harvest In JUD 1:12 a literal rendering of ‘even in autumn’ might be misleading in some areas in which autumn as a calendrical term might not be the period for bearing fruit. Therefore, it might be better to translate JUD 1:12 as ‘trees that bear no fruit even in the season when they should.’
UBS Dictionary of the Greek New Testament © United Bible Societies, licensed CC BY-SA 4.0.
Thayer's Greek Lexicon
ἄ-καρπος, -ov, (καρπός), [fr. Aeschyl. down], without fru, barren; 1. prop.: δένδρα, Jude 12. 2. metaph. not yielding what it ought to yield, [A. V. unfruitful]: Mt. xiii. 22; Mk. iv. 19; destitute of good deeds, Tit. iii. 14; 2 Pet. i. 8; contributing nothing to the instruction, improvement, comfort, of others, 1 Co. xiv. 14; by litotes pernicious, Eph. ν. 11, (Sap. xv. 4; οἵ. Grimm on Sap. i. 11).
Mounce Concise Greek Dictionary
ἄκαρπος akarpos 7x
without fruit, unfruitful, barren; by impl. noxious
Abbott-Smith Greek Lexicon
ἄ-καρπος, -ον,
[in LXX: Je 2:6 (צַלְמָוֶת), Wi 15:4, IV Mac 16:7;]
unfruitful, barren: fig., Mt 13:22, Mk 4:19, I Co 14:14, Eph 5:11, Tit 3:14, II Pe 1:8, Ju 12.†
Moulton & Milligan — Vocabulary of the Greek NT
ἄκαρπος. The adj. may be cited from P Oxy I. 535 (a.p. 316) ὅθ[εν] ἐφῖδον τὴν περσείαν ἄκαρπον οὖσαν πολλ[ῶ)ν ἐτῶν Part I. ’ , ακαταστατος διόλου ξηραντῖσαν. For the subst. see Sy// 420% (i/a.p.) διὰ τὰς γενομένας eblet]ns ἀκαρπίας τῶν ἐλαιῶν.
Liddell-Scott-Jones — Greek-English Lexicon
ἄκαρπος (akarpos) — unfruitful. ἄκαρπ-ος, ον, without fruit, barren, [Refs 5th c.BC+]; ἄ. ξύλον, ={ἀκακία}, [LXX+2nd c.AD+]
2. metaphorically, fruitless, unprofitable, πόνος[Refs 5th c.BC+]. adverb -πως[Refs 5th c.BC+]
II. active, making barren, [Refs 4th c.BC+]