Clam_upWordNet ExplorerExplore synonyms, antonyms, hypernyms, hyponyms, and semantic relationships for “clam_up” powered by Princeton WordNet.verbrefuse to talk or stop talking; fall silentWords in this synset: close_up, dummy_up, shut_up, belt_up, button_up, be_quiet, keep_mum📖 Dictionary definition🌍 Word origin & etymology