Quick Definition
ἄφρων, ονος, ον Adj senseless, foolish, inconsiderate
Strong's Definition
from 1 (as a negative particle) and 5424; properly, mindless, i.e. stupid, (by implication) ignorant, (specially) egotistic, (practically) rash, or (morally) unbelieving
KJV Usage: fool(-ish), unwise
UBS Dictionary of the Greek New Testament
adjc. | -ον, -ονος | ἀ- + φρονέω
32.52 · Understand · Lack of Capacity for Understanding
foolish, senseless, unwise pertaining to not employing one’s understanding, particularly in practical matters It is possible that ἄφρων in ROM 2:20 (παιδευτὴν ἀφρόνων ‘instructor of the foolish’) refers to people who are simply uninstructed or ignorant, since ἀφρόνων could be parallel with νηπίων, occurring in the same verse. On the other hand, there appears to be a contrast in the meanings of ἀφρόνων and νηπίων because of the distinctiveness in meanings of παιδευτήν and διδάσκαλον. Therefore, ἄφρων in ROM 2:20 is better understood as referring to those who act foolishly because they do not use their potential for understanding.
LUK 11:40 · LUK 12:20 · ROM 2:20 · 1CO 15:36 · 2CO 11:16 · 2CO 11:16 · 2CO 11:19 · 2CO 12:6 · 2CO 12:11 · EPH 5:17 · 1PE 2:15
UBS Dictionary of the Greek New Testament © United Bible Societies, licensed CC BY-SA 4.0.
Thayer's Greek Lexicon
ἄφρων, -ovos, ὁ, 7), -ov, τό, (fr. a priv. and φρήν, cf. εὖὔῴρων, σώφρων), [fr. Hom. down], prop. without reason ([εἴδωλα, Xen. mem. 1, 4, 4]; of beasts, ibid. 1, 4, 14), senseless, foolish, stupid ; without reflection or intelligence, acting rashly: Lk. xi. 40; xii. 20; Ro. ii. 20; 1 Co. xv. 36; 2 Co. xi. 16, 19 (opp. to φρόνιμος, asin Prov. xi. 29) ; 2 Co. xii. 6,11; Eph. ν. 17 (opp. to συνιέντες); 1 Pet. ii. 15. [A strong term; cf. Schmidt ch. 147 § 17.]
Mounce Concise Greek Dictionary
ἄφρων aphrōn 11x
unwise, inconsiderate, simple, foolish, Lk. 11:40; 12:20; 1 Cor. 15:36; ignorant, religiously unenlightened, Rom. 2:20; Eph. 5:17; 1 Pet. 2:15; boastfully foolish, vain, 2 Cor. 11:16, 19
Abbott-Smith Greek Lexicon
ἄφρων, -ον gen. -ονος
(< φρήν), [in LXX for כְּסִיל, נָבָל, etc.;]
without reason, senseless, foolish, expressing "want of mental sanity and sobriety, a reckless and inconsiderate habit of mind" (Hort; cf. MM, s.v.): Lk 11:40 12:20, Ro 2:20, I Co 15:36, II Co 11:16 12:6, 11, I Pe 2:15; opp. to φρόνιμος, II Co 11:19; to συνιέντες, Eph 2:17.†
Moulton & Milligan — Vocabulary of the Greek NT
ἄφρων. P Fay 124! (ii/A.D.) πάνυ yap μοι δοκεῖς ἄφρων τις εἴ[ν]αι, ‘indeed you appear to me to be quite mad” (Edd.) —a remonstrance addressed to a man who was defrauding his mother of some allowance. The adj. occurs in the literary P Grenf I. 119 (ii/b.c.) ἐὰν δ᾽ ἑνὶ προσκαθεῖ μόνον, ἄφρων ἔσει : see note.
Liddell-Scott-Jones — Greek-English Lexicon
ἄφρων (aphrōn) — foolish. ἄφρων, ον, genitive ονος, (φρήν) senseless, of statues, [Refs 5th c.BC+]:— and so, crazed, frantic, ἄφρονα κούρην[Refs 8th c.BC+]; silly, foolish, [Refs 8th c.BC+]; τὸ ἄ., ={ἀφροσύνη}, [Refs 5th c.BC+]; τῶ φρονίμῳ τῆς γνώμης παύοντες τὸ ἄ. [τῆς ῥώμης] [Refs 5th c.BC+]: comparative -έστερος[Refs 5th c.BC+]: superlative -έστατος[Refs 5th c.BC+]. adverb -νως senselessly, [Refs 5th c.BC+]; opposed to νοῦν ἐχόντως, [Refs 5th c.BC+]: comparative -εστέρως[Refs 5th c.BC+] -έστερον [Refs 4th c.AD+]
2. ἄφρων, ={κώνειον}, Ps.-[Refs 1st c.AD+]