- 1underpin something (formal) to support or form the basis of an argument, a claim, etc. The report is underpinned by extensive research.
- 2underpin something (technology) to support a wall by putting metal, concrete, etc. under it
NAmE//ˌʌndərˈpɪn//Verb Forms present simple I / you / we / they underpin
he / she / it underpins
past simple underpinned
-ing form underpinning
underpinningjump to other results
NAmE//ˈʌndərˌpɪnɪŋ//noun [countable, uncountable]