entrain (v.1)

"to draw along," 1560s, a term in chemistry, from French entrainer (12c.), from en- "away" (see en- (1)) + trainer "to drag" (see train (n.)). Related: Entrained; entrainment.

entrain (v.2)

"get on board a locomotive train," 1860s, from en- (1) "in, into" + train (n.). Related: Entrained.