(1) Usually a substantive (mathetes, "a learner," from manthano, "to learn"; Latin discipulus, "a scholar"): The word is found in the Bible only in the Gospels and Acts. But it is good Greek, in use from Herodotus down, and always means the pupil of someone, in contrast to the master or teacher (didaskalos). See Mt 10:24; Lk 6:40. In all cases it implies that the person not only accepts the views of the teacher, but that he is also in practice an adherent. The word has several applications. In the widest sense it refers to those who accept the teachings of anyone, not only in belief but in life. Thus the disciples of John the Baptist (Mt 9:14; Lk 7:18; Jn 3:25); also of the Pharisees (Mt 22:16; Mk 2:18; Lk 5:33); of Moses (Jn 9:28). But its most common use is to designate the adherents of Jesus. (a) In the widest sense (Mt 10:42; Lk 6:17; Jn 6:66, and often). It is the only name for Christ's followers in the Gospels. But (b) especially the Twelve Apostles, even when they are called simply the disciples (Mt 10:1; 11:1; 12:1, et al.). In the Acts, after the death and ascension of Jesus, disciples are those who confess Him as the Messiah, Christians (Acts 6:1,2,7; 9:36 (feminine, mathetria); Acts 11:26, "The disciples were called Christians"). Even half-instructed be-lievers who had been baptized only with the baptism of John are disciples (Acts 19:1-4).
(2) We have also the verb, matheteuo, "Jesus' disciple" (literally, "was discipled to Jesus," Mt 27:57); "Make disciples of all the nations" (the King James Version "teach," Mt 28:19); "had made many disciples" (the King James Version "taught many," Acts 14:21); "every scribe who hath been made a disciple to the kingdom of heaven" (the King James Version "instructed," Mt 13:52). The disciple of Christ today may be described in the words of Farrar, as "one who believes His doctrines, rests upon His sacrifice, imbibes His spirit, and imitates His example."
The Old Testament has neither the term nor the exact idea, though there is a difference between teacher and scholar among David's singers (1 Ch 25:8), and among the prophetic guilds the distinction between the rank and file and the leader (1 Sam 19:20; 2 Ki 6:5).
G. H. Trever
(taken from International Standard Bible Encyclopedia)