Quick Definition
δεκάτη, ης, ἡ Adj a tenth part, a tithe
Strong's Definition
a tenth, i.e. as a percentage or (technically) tithe
Derivation: feminine of G1182 (δέκατος);
KJV Usage: tenth (part), tithe
Thayer's Greek Lexicon
δεκάτη, -ης, ἡ; (δέκατος), the tenth part of any thing, a tithe; specially the tenth part of booty taken from the enemy: Heb. vii. 2,4; the tithes of the fruits of the earth and of the flocks, which, by the law of Moses, were presented to the Levites in the congregation of Israel: Heb. vii. 8 sq. (In Grk. writ. fr. [Simon. 133 Bgk. ; Hat. 2, 135]; 4, 152 down; Sept. for wyn.) (Cf. BB.DD. s. v. Tithe.]
Mounce Concise Greek Dictionary
δέκατος dekatos 7x
tenth, Jn. 1:39; Rev. 11:13; 21:20; δεκάτη, i.e. μερίς, a tenth part, tithe, Heb. 7:2, 4, 8, 9*
Abbott-Smith Greek Lexicon
δεκάτη, -ης, ἡ prop. fem. (sc. μέρος) of δέκατος, -η, -ον,
[in LXX for מַעֲשֵׂר: Ge 14:20, Ne 12:44, et al. ;]
a tenth part, a tithe: He 7:2, 4, 8, 9 (for a curious inversion of the Biblical use, v. MM, s.v.).†
Moulton & Milligan — Vocabulary of the Greek NT
δεκάτη. The original ἀπόμοιρα paid to the temples on the produce of vineyards, palm-groves, etc. would seem to have been ith, but this was reduced by the Government to ;/pth in the case of certain favoured classes: see P Rev L 24410 with the editors’ notes. An odd inversion of the Jewish conception of tithes comes in P Hib I. 115? (¢. B.C. 250) where, according to the editors, the μόσχων δεκάτης refers to a 10 per cent. duty levied upon the profits obtained by the priests from calves offered for sacrifice at the temple: see also the introduction to P Tebt II. 307 (A.D. 208) and Wilcken Ostr. i. p. 384 f.
Liddell-Scott-Jones — Greek-English Lexicon
δεκάτη (dekatē) — tenth. δέκᾰτος [Refs 4th c.AD+] δέκοτος [Refs 5th c.BC+], also Aeolic dialect in [Refs], η, ον: (δέκα):— tenth, Ἠώς [Refs 8th c.BC+]; as a round number, [Refs 8th c.BC+]
II. δεκάτη (i.e. μερίς), ἡ, tenth part, tithe, τᾶς δεκάτας δεκάταν [Refs 5th c.BC+]; τὰ ἐκ τῆς δ. the produce of the tenth, [Refs 4th c.BC+]
II.2. δεκάτη (i.e. ἡμέρα), ἡ, the tenth day, [Refs 8th c.BC+]
II.2. b δ. προτέρα· ἡ πρὸ εἰκάδος, ὡς ὑστέρα· ἡ μετ᾽ εἰκάδα, [Refs 5th c.AD+]
II.3. festival on the tenth day after birth, when the child has a name given it, τὴν δ. θύειν to give a naming-day feast, [Refs 5th c.BC+]
II.4. δεκάτα· τάξις, ἄθροισμα, καὶ ἡ τῶν εἴκοσιν ἁρμάτων τάξις, [Refs 5th c.AD+]
II.5. δέκατον, τό, tenth part, [LXX]