From (a presumed derivative of) genos; a generation; by implication, an age (the period or the persons) -- age, generation, nation, time.
see GREEK genos
1. a begetting, birth, nativity: Herodotus 3, 33; Xenophon, Cyril 1, 2, 8, etc.; (others make the collective sense the primary significance, see Curtius as above).
2. passively, that which has been begotten, men of the same stock, a family;
a. properly, as early as Homer; equivalent to מִשְׁפָּחַה, Genesis 31:3, etc. σῴζειν Ρ᾽αχαβην καί τήν γενεάν αὐτῆς, Josephus, Antiquities 5, 1, 5. the several ranks in a natural descent, the successive members of a genealogy: Matthew 1:17 (ἑβδόμῃ γενεά οὗτος ἐστιν ἀπό τοῦ πρώτου, Philo, vit. Moys. i. § 2).
b. metaphorically, a race of men very like each other in endowments, pursuits, character; and especially in a bad sense a perverse race: Matthew 17:17; Mark 9:19; Luke 9:41; Luke 16:8; (Acts 2:40).
3. the whole multitude of men living at the same time: Matthew 24:34; Mark 13:30; Luke 1:48 (πᾶσαι αἱ γενεαί); 4. an age (i. e. the time ordinarily occupied by each successive generation), the space of from 30 to 33 years (Herodotus 2, 142, et al.; Heraclitus in Plutarch, def. orac. c. 11), or ὁ χρόνος, ἐν ᾧ γεννωντα παρέχει τόν ἐξ αὐτοῦ γεγεννημένον ὁ γεννησας (Plutarch, the passage cited); in the N. T. common in plural: Ephesians 3:5 (Winers Grammar, § 31, 9 a.; Buttmann, 186 (161)); παρῳχημέναις γενεαῖς in ages gone by, Acts 14:16; ἀπό τῶν γενεῶν for ages, since the generations began, Colossians 1:26; ἐκ γενεῶν ἀρχαίων from the generations of old, from ancient times down, Acts 15:21; εἰς γενεάς γενεῶν unto generations of generations, through all ages, forever (a phrase which assumes that the longer ages are made up of shorter; see αἰών, 1 a.): Luke 1:50 R L (דּורִים לְדור, Isaiah 51:8); εἰς γενεάς καί γενεάς unto generations and generations, ibid. T Tr WH equivalent to וָדור לְדור, Psalm 89:2; Isaiah 34:17; very often in the Sept.; (add, εἰς πάσας τάς γενεάς τοῦ αἰῶνος τῶν αἰώνων, Ephesians 3:21, cf. Ellicott at the passage) (γενεά is used of a century in Genesis 15:16, cf. Knobel at the passage, and on the senses of the word see the full remarks of Keim, iii. 206 (v. 245 English translation)).