In music, a motive is

Is a short musical idea,[5] a salient recurring figure, musical fragment or succession of notes that has some special importance in or is characteristic of a composition: "The motive is the smallest structural unit possessing thematic identity". [3]

A motive in music can also be referred to as a motif. Which means it is a short musical idea, a noticeable and recurring figure and/or a musical fragment of notes that have a special importance in a composition.