Impound rhymes with:
expound, lb, pound, propound, abound, aground, around, astound, bound, browned, confound, crowned, downed, drowned, expound, found, frowned, ground, hound, inbound, lb, mound, newfound, pound, profound, propound, rebound, redound, renowned, resound, round, sound, surround, ultrasound, unbound, unsound, unwound, wound
Impound sounds like:
impend, impounded, impunity, inabinet, inbound, infant, infante, infinite, infiniti, infinity, invent, invented