"All nations" are to be discipled and brought under His sway,—such is the commission; and to whom is it given?
Old English discipul (fem. discipula), Biblical borrowing from Latin discipulus "pupil, student, follower," said to be from discere "to learn" [OED, Watkins], from a reduplicated form of PIE root *dek- "to take, accept" (see decent).
But according to Barnhart and Klein, from a lost compound *discipere "to grasp intellectually, analyze thoroughly," from dis- "apart" (see dis-) + capere "to take, take hold of" (see capable). Cf. Latin capulus "handle" from capere. Sometimes glossed in Old English by þegn (see thane).