Lexical Definition

‎αἵρεσις‎ haíresis (hah'-ee-res-is) sect G:N-F
from ‎αἱρέομαι‎

heresy (which is the Greek word itself), sect.

Usage: 6 forms in 12 verses
Form Translated As     In Verse(s)
αἵρεσισ sect Acts.5.17
αἵρεσιν a sect Acts.24.14
sect Acts.26.5
αἱρέσεωσ sect Acts.15.5Acts.24.5Acts.28.22
αἱρέσεισ factions 1Cor.11.19Gal.5.20
heresies 2Pet.2.1
αιρέσεωσ their sects LXX.Gen.49.5
αίρεσιν a choice LXX.Lev.22.21
choice LXX.Lev.22.18

Abbott-Smith

αἵρεσις, -εως, ἡ (< αἱρέω, -ομαι), [in LXX for נְדָבָה,]
1. capture.
2. choosing, choice (v. MM, VGT, s.v.).
3. that which is chosen, hence, opinion; esp. a peculiar opinion, heresy: I Co 11:19, Ga 5:20, II Pe 2:1, R, txt.
4. In late writers (MM, VGT), of a set of persons professing particular principles or opinions, a school, sect, party, faction: Ac 5:17 15:5 24:5, 14 26:5 28:22, I Co 11:19, Ga 5:20, II Pe 2:1, R, mg. (Cremer, 614).†

Abbott-Smith References

Book Refs
Acts 5:17 · 15:5 · 24:5 · 24:14 · 26:5 · 28:22
1 Corinthians 11:19
Galatians 5:20
2 Peter 2:1

Liddell-Scott-Jones

αἵρεσις, εως, ,

taking, especially of a town, [Refs 5th c.BC+]; βασιλέος αἵ. the taking by the king, [Refs 5th c.BC+]; αἵ. δυνάμεως acquisition of power, [Refs 5th c.BC+]:—generally, taking, receiving, ἐπιγενημάτων[Refs 2nd c.BC+]

__B (αἱρέομαι) choice, αἵρεσίν τ᾽ ἐμοὶ δίδου[Refs 5th c.BC+]; followed by relative, αἵ. διδόναι ὁκοτέρην.., εἰ.., etc., [Refs 5th c.BC+]; αἵ. προτιθέναι, προβάλλειν, [Refs 5th c.BC+]; οὐκ ἔχει αἵρεσιν it admits no choice, [Refs 1st c.AD+]
__B.2 choice, election of magistrates, [Refs 5th c.BC+]
__B.3 inclination, choice, πρός τινα Philipp. cited in [Refs 4th c.BC+]; opposed to φυγή, [Refs 4th c.BC+]; περὶ αἱρέσεων καὶ φυγῶν, title of treatise by Epicurus.
__B.II purpose, course of action or thought, like{προαίρεσις}, [Refs 5th c.BC+]; αἵ. Ἐλληνική the study of Greek literature, [Refs 2nd c.BC+]:—conduct, [Refs 2nd c.BC+]
__B.II.2 system of philosophic principles, or those who profess such principles, sect, school, [Refs 2nd c.BC+]; κατὰ τῶν αἱ., title of treatise by Antipater of Tarsus; περὶ αἱρέσεων, title of Menippean satire by Varro,[Refs]; αἵρεσις πρὸς Γοργιππίδην, title of work by Chrysippus, [Refs 3rd c.AD+]; especially religious party or sect, of the Essenes, [NT+1st c.AD+], generally, faction, party, [Refs 2nd c.AD+]
__B.II.3 corps of epheboi, [Refs]
__B.II.4 Astrology texts, 'condition', [Refs 2nd c.AD+]
__B.III proposed condition, proposal, [Refs 1st c.BC+]
__B.III.2 commission, ἐπὶ τοὺς νέους αἵ. [Refs 5th c.BC+]; embassy, mission, [Refs]
__B.III.3 freewill offering, opposed to vow, [LXX]
__B.III.4 bid at auction, τὴν ἀμείνονα αἵ. διδόντι παραδοθῆναι[Refs 2nd c.AD+]

LSJ Scripture Refs: Acts.5.17LXX.Lev.22.18