1. absolutely, for the Hebrew קַנָּא, used of God as jealous of any rival and sternly vindicating his control: Exodus 20:5; Deuteronomy 4:24, etc. From the time of the Maccabees () there existed among the Jews a class of men, called Zealots, who rigorously adhered to the Mosaic law and endeavored even by a resort to violence, after the example of Phinehas (Numbers 25:11, ζηλωτής Φινης 4 Macc. 18:12), to prevent religion from being violated by others; but in the latter days of the Jewish commonwealth they used their holy zeal as a pretext for the basest crimes, Josephus, b. j. 4, 3, 9; 4, 5, 1; 4, 6, 3; 7, 8, 1. To this class perhaps Simon the apostle had belonged, and hence, got the surname ὁ ζηλωτής: Luke 6:15; Acts 1:13; (cf. Schürer, Neutest. Zeitgesch., Index under the word Zeloten; Edersheim, Jesus the Messiah, i. 237ff).

2. with the genitive of the object: with the genitive of the thing, most eagerly desirous of, zealous for, a thing;

a. to acquire a thing (zealous of) (see ζηλόω, 2): 1 Corinthians 14:12; Titus 2:14; 1 Peter 3:13 L T Tr WH (ἀρετῆς, Philo, praem. et poen. § 2; τῆς εὐσεβείας, de monarch. 50:1, § 3; εὐσεβείας καί δικαιοσύνης, de poenit. § 1; τῶν πολεμικων ἔργων, Diodorus 1, 73; περί τῶν ἀνηκόντων εἰς σωτηρίαν, Clement of Rome, 1 Cor. 45, 1 [ET]).

b. to defend and uphold a thing, vehemently contending for a thing (zealous for): νόμου, Acts 21:20 (2 Macc. 4:2); τῶν πατρικῶν παραδόσεων, Galatians 1:14 (τῶν αἰγυπτιακων πλασματων, Philo, vit. Moys. iii. § 19; τῆς ἀρχαίας καί σώφρονος ἀγωγης, Diodorus excerpt., p. 611 (from 50:37, vol. 2:564 Didot)); with the genitive of person: Θεοῦ, intent on protecting the majesty and authority of God by contending for the Mosaic law, Acts 22:3. (In secular authors also an emulator, admirer, imitator, follower of anyone.)