Lexical Definition

‎αἴτιος‎ aítios (ah'-ee-tee-os) causer ^G:A
from the same as ‎αἰτέω‎

author.

• causative, i.e. (concretely) a causer

Abbott-Smith

αἴτιος, -α, ὁ (< αἰτία), [in LXX: I Ki 22:22 (סבב) Da LXX Bel 41, TH Da Bel 42, Su 53, II Mac 4:47 13:4, IV Mac 1:11*;]

1. causative of, responsible for; as subst., ὁ αἰ., the cause, author: He 5:9; τὸ αἰ., the cause, Ac 19:40.
2. blameworthy, culpable; as subst., ὁ αἰ., the culprit, the accused (Lat. reus); τὸ αἰ. (= αἰτία, 3), the crime, Lk 23:4, 14, 22.†

Abbott-Smith References

Liddell-Scott-Jones

form of: αἴτιον

αἴτιος-ος, α, ον,

more rarely ος, ον [Refs 5th c.BC+]:— culpable, responsible, ἐπεὶ οὔ τί μοι αἴτιοςοί εἰσιν[Refs 8th c.BC+]: comparative αἰτιώτερος[Refs 5th c.BC+] the most guilty, [Refs 5th c.BC+]

__2 substantive, αἴτιοςος, ὁ, the accused, the culprit, [Refs 4th c.BC+]; οἱ αἴ. τοῦ πατρός they who have sinned against my father, [Refs]:—with genitive of things, οἱ αἴ. τοῦ φόνου[Refs 5th c.BC+]
__II responsible for, with genitive of things, [Refs 5th c.BC+]; αἴτιοςός τινός τινι being the cause of a thing to a person, [Refs 5th c.BC+]: with infinitive, αἴ. τὸν ἠέρα ξηρὸν εἶναι[αἴτιοςος τὸ σὲ ἀποκρίνασθαι 5th-6th c.BC: Plato Philosophus “Laches” 190e">Refs 5th c.BC+]: comparative, τοῦ.. ἐλευθέραν εἶναι.. αἰτιώτερον[Refs 4th c.BC+] mainly instrumental in causing the sea-fight, [Refs 5th c.BC+]
__II.2 αἴτιοςον, τό, cause, [Refs 5th c.BC+]; τί ποτ᾽ οὖν ἐστι τὸ αἴτιοςον τό.. μηδένα εἰπεῖ; [Refs 5th c.BC+]