From Longman Dictionary of Contemporary Englishput a sock in itput a sock in itinformalTALK TO somebody used to tell someone in a joking way to stop talking or making a noise → sock
Examples from the Corpus
put a sock in it• To avoid upsetting the kids, Dad spoke to Mum more than once in private, telling her to put a sock in it.• That sort does all sorts of silly things, till experience tells them to put a sock in it. 