Make firm
Stop up
Stop up verb - To prevent passage through by filling with something.
Cite this Source
Stop up and Make firm. (2016). Retrieved 2026, August 13, from https://thesaurus.plus/related/make_firm/stop_up
Make firm & Stop up. N.p., 2016. Web. 13 Aug. 2026. <https://thesaurus.plus/related/make_firm/stop_up>.
Stop up or Make firm. 2016. Accessed August 13, 2026. https://thesaurus.plus/related/make_firm/stop_up.
Google Ngram Viewer shows how "make firm" and "stop up" have occurred on timeline