- 1[transitive] firm something to make something become stronger or harder Firm the soil around the plant. This product claims to firm your body in six weeks.
- 2 [intransitive] firm (to/at…) (finance) (of shares, prices, etc.) to become steady or rise steadily The company's share price has firmed in recent days. Phrasal Verbsfirm upfirm up something
NAmE//fərm//Verb Forms present simple I / you / we / they firm
he / she / it firms
past simple firmed
-ing form firming