Quick Definition
I speak or say in opposition, I contradict
Strong's Definition
to refute or deny
Derivation: from G473 (ἀντί) and G2036 (ἔπω);
KJV Usage: gainsay, say against
Thayer's Greek Lexicon
ἀντεῖπον, a 2 aorist used instead of the verb ἀντιλέγειν, to speak against, gainsay; (from Aeschylus down): Luk_21:15; Act_4:14. Cf. εἶπον.
Mounce Concise Greek Dictionary
ἀντιλέγω antilegō 11x
to speak against, contradict; to gainsay, deny, Luk_20:27 ; to oppose, Joh_19:12 ; Act_13:45 ; Act_28:19 ; Rom_10:21 ; Tit_1:9 ; Tit_2:9 ; pass. to be spoken against, decried, Luk_2:34 ; Act_28:22 * contradict; rebel; speak against.
Abbott-Smith Greek Lexicon
ἀντ -εῖπον
(άντί , εἶτον ),
[in LXX for H7725 hi ., H1696 pi ., H6030 , etc.;]
2 aor. , without present in use, to speak against, gainsay: Luk_21:15 , Act_4:14 .†
STEPBible — Tyndale Abridged Greek Lexicon
ἀντ-εῖπον
(άντί, εἶτον), [in LXX for H7725 hi., דָבַר pi., עָנָה, etc. ;]
__2 2 aor., without present in use, to speak against, gainsay: Luk.21:15, Act.4:14.†
(AS)