Quick Definition
Ἑβραΐς, ΐδος, ἡ n.f. the Hebrew language, Aramaic
Strong's Definition
the Hebraistic (Hebrew) or Jewish (Chaldee) language
Derivation: from G1443 (Ἐβέρ);
KJV Usage: Hebrew
UBS Dictionary of the Greek New Testament
adjc. | -ΐδος
93.104 · Names of Persons and Places · Persons
Hebrew (derivative of Εβραῖος ‘a Hebrew,’ 93.105) pertaining to the Hebrews The addition of γράμμασιν in some manuscripts literally applies to Hebrew letters, though the reference seems to be to the language, probably Aramaic. In ACT 21:40 ACT 22:2 ACT 26:14 a peculiar form of Ἑβραϊκός occurs, namely, Ἑβραΐδι. Scholars, however, explain it as from Ἑβραΐς, relating it to Εβραῖος (93.105).
UBS Dictionary of the Greek New Testament © United Bible Societies, licensed CC BY-SA 4.0.
Thayer's Greek Lexicon
Mounce Concise Greek Dictionary
Ἑβραίς Hebrais 3x
the Hebrew dialect, i.e., the Hebrew-Aramaic dialect of Palestine, Acts 21:40; 22:2; 26:14*
Abbott-Smith Greek Lexicon
**† Ἑβραΐς (WH, Ἐβ-), -ίδος (Aram. עִבְרַי), peculiar form of Ἑβραϊκός,
[in LXX, ἡ Ἑ. φωνή, IV Mac 12:7 16:15 * ;]
in NT, ἡ Ἑ. διάλεκτος, Hebrew, i.e. the Aramaic vernacular of Palestine: Ac 21:40 22:2 26:14.†
Liddell-Scott-Jones — Greek-English Lexicon
Ἑβραΐς (Hebrais) — Hebrew. “Hebrew”: and as substantive, a Hebrew, [NT+2nd c.AD+]:— adjective Ἑβραϊκός, ή, όν, [NT]:—feminine Ἑβραΐς, ίδος, διάλεκτος [NT+1st c.AD+]:—Verb Ἑβραΐζω, speak Hebrew, [Refs]:— adverb Ἑβραϊστί, in the Hebrew tongue, LXX Si.prol., [NT]