Quick Definition
an interjection: ho!
Strong's Definition
properly, let it be, i.e. (as interjection) aha!
Derivation: apparent imperative of G1439 (ἐάω);
KJV Usage: let alone
Thayer's Greek Lexicon
ἔα, an interjection expressive of indignation, or of wonder mixed with fear (derived apparently from the imperative present of the verb ἐάν (according to others a natural instinctive, sound)), frequent in the Attic poets, rare in prose writings (as Plato, Prot., p. 314 d.), "Ha! Ah!": Mar_1:24 R G; Luk_4:34; cf. Fritzsche on Mark, p. 32f.
Mounce Concise Greek Dictionary
ἔα ea 1x
Ha! an expression of surprise or displeasure, Luk_4:34
Abbott-Smith Greek Lexicon
ἔα ,
interj., expressing surprise, indignation, fear (in cl . chiefly in poλt.),
ah! ha!: Luk_4:34 .†
STEPBible — Tyndale Abridged Greek Lexicon
ἔα,
interj.,
expressing surprise, indignation, fear (in cl. chiefly in poët.), ah! ha!: Luk.4:34.†
(AS)