Clashing rhymes with:
flashing, lashing, slashing, splashing, bashing, caching, cashing, crashing, dashing, fasching, flashing, gnashing, hashing, lashing, rehashing, slashing, smashing, splashing, stashing, thrashing, trashing
Clashing sounds like:
calgene's, calkins, callousness, caulking, caulkins, chalking, clackamas, classing, clausing, clicking, cloaking, clocking, clogging, closeness, closing, closings, clucking, coalescence, coalescing, collegians, collisions