Tough
Tough adjective - Not easily chewed.
Unsusceptible and tough are semantically related. In some cases you can use "Unsusceptible" instead an adjective "Tough".
Unsusceptible
Unsusceptible adjective - Not susceptible to.
Tough and unsusceptible are semantically related. Sometimes you can use "Tough" instead an adjective "Unsusceptible".
Mutual synonyms
Cite this Source
Unsusceptible and Tough. (2016). Retrieved 2026, July 28, from https://thesaurus.plus/related/tough/unsusceptible
Tough & Unsusceptible. N.p., 2016. Web. 28 Jul. 2026. <https://thesaurus.plus/related/tough/unsusceptible>.
Unsusceptible or Tough. 2016. Accessed July 28, 2026. https://thesaurus.plus/related/tough/unsusceptible.
Google Ngram Viewer shows how "tough" and "unsusceptible" have occurred on timeline