Lexical Definition

‎πρῶτος‎ prōtos (pro'-tos) first ^G:A
contracted superlative of ‎πρό‎

before, beginning, best, chief(-est), first (of all), former.

• foremost (in time, place, order or importance)

Abbott-Smith

B. Superl., πρῶτος, -η, -ον, [in LXX chiefly for רִאשׁוֹן, also for אֶחַד, etc.;]
first,
1. of Time or Place;
(a) absol., as subst., ὁ π.., Lk 14:18, Jo 19:32, I Co 14:30; ὁ π. καὶ ὁ ἔσχατος, Re 1:17 2:8 22:13; neut., τὸ π., opp. to τ. δεύτερον, He 10:9; τὰ π., opp. to τ. ἔσχατα, Mt 12:45, Lk 11:26, II Pe 2:20; anarth., Mt 10:2; pl., Mt 19:30, Mk 10:31, Lk 13:30; ἐν πρώτοις (EV, first of all), I Co 15:3;
(b) as adj.: πρώτῃ (sc. ἡμέρᾳ) σαββάτου, 9]; φυλακή, opp. to δευτέρα, Ac 12:10; equiv. to adv. in English, 7] 20:4, 8, Ac 27:43, Ro 10:19, I Ti 1:16, I Jo 4:19; = πρότερος (v. infr.; cf. M, Pr., 79; Bl., § 11, 5; Thackeray, Gr., 183 f.): c. gen., π. μου ἦν (my chief: Abbott, Jg., 509 ff.; but cf. M, Pr., 245), Jo 1:15, 30; c. art., Mk 14:12, Ac 1:1, al.; seq. ὁ δεύτερος, etc., Mt 22:25, Mk 12:20, al.
2. Of Rank or Dignity, chief, principal: Mt 20:27 22:38, Mk 9:35, Eph 6:2, al.; c. gen., Mk 12:28, 29 al.; πόλις (Field, Notes, 124), Ac 16:12; c. art., Lk 15:22 19:47, Ac 13:50, al.
3. Neut., πρῶτον, as adv., first, at the first;
(a) of Time: Mt 8:21, Mk 4:28, al.; τὸ π., Jo 10:40, al.;
(b) of Order: Ro 3:2, I Co 11:18, al.

Abbott-Smith References

Liddell-Scott-Jones

πρῶτος, η, ον,

see at {πρότερος} [Refs 5th c.BC+]