Origin: Abbrev. Fr. Impester, fr. OF. Empaistrier, empestrer, to entangle the feet or legs, to embarrass, F. Empetrer; pref. Em-, en- (L. In in) _ LL. Pastorium, pastoria, a fetter by which horses are prevented from wandering in the pastures, fr. L. Pastorius belonging to a herdsman or shepherd, pastor a herdsman. See In, and Pasture, Pastor.