Clam up
Clam up verb - To stop talking.
Make fast
Mutual synonyms
Cite this Source
Make fast and Clam up. (2016). Retrieved 2026, August 16, from https://thesaurus.plus/related/clam_up/make_fast
Clam up & Make fast. N.p., 2016. Web. 16 Aug. 2026. <https://thesaurus.plus/related/clam_up/make_fast>.
Make fast or Clam up. 2016. Accessed August 16, 2026. https://thesaurus.plus/related/clam_up/make_fast.
Google Ngram Viewer shows how "clam up" and "make fast" have occurred on timeline