(ʌndəʳpɪn )

Word forms: 3rd person singular present tense underpins, present participle underpinning, past tense, past participle underpinned

verb

If one thing underpins another, it helps the other thing to continue or succeed by supporting and strengthening it.

…mystical themes that underpin all religions. [VERB noun] 

…the beliefs underpinning contemporary art. [VERB noun] 

…a style of life extensively underpinned by public money. [VERB noun] 

underpinningWord forms: plural underpinningsvariable noun

…the economic underpinning of ancient Mexican society. [+ of] 

Many questioned the moral underpinnings of our financial dealings with each other. [+ of] 

Synonyms: support, base, foundation, footing  More Synonyms of underpin

https://www.collinsdictionary.com/dictionary/english/underpin