Synonyms to clam up

button up, bang, bar, barricade, batten, batten down, bolt, button, cap, carry to completion, choke, choke off, clap, clean up, climax, close, close out, close up, complete, conclude, constrict, contain, contract, cover, crown, culminate, dummy up, end, fasten, finalize, finish, finish off, finish up, fold, fold up, get done, get it over, get through, get through with, key, latch, lock, lock out, lock up, mop up, occlude, padlock, perfect, plumb, round out, seal, seal off, seal up, secure, shut, shut the door, shut up, slam, snap, squeeze shut, strangle, terminate, top off, top out, wind up, wrap up, zip up, zipper