A DISCIPLE IS ?

Vine’s Expository Dictionary Defines a Disciple As;

1. mathetes NT:3101, lit., "a learner" (from manthano, "to learn," from a root math—, indicating thought accompanied by endeavor), in contrast to didaskalos, "a teacher"; hence it denotes "one who follows one's teaching," as the "disciples" of John, Matt 9:14; of the Pharisees, Matt 22:16; of Moses, John 9:28; it is used of the "disciples" of Jesus (a) in a wide sense, of Jews who became His adherents, John 6:66; Luke 6:17, some being secretly so, John 19:38; (b) especially of the twelve apostles, Matt 10:1; Luke 22:11, e. g.; (c) of all who manifest that they are His "disciples" by abiding in His Word, John 8:31, cf. 13:35; 15:8; (d) in the Acts, of those who believed upon Him and confessed Him, 6:1,2,7; 14:20,22,28; 15:10; 19:1, etc.

A "disciple" was not only a pupil, but an adherent; hence they are spoken of as imitators of their teacher; cf. John 8:31; 15:8.