toughen

From Wiktionary

Word parts[change]

tough + -en

Pronunciation[change]

Verb[change]

Plain form
toughen

Third-person singular
toughens

Past tense
toughened

Past participle
toughened

Present participle
toughening

  1. (transitive) If you toughen something, you make it tough.
  2. (intransitive) If something toughens, it becomes tough.

Related words[change]