- To lay stones, masonry, etc., under, as the sills of a
building, on which it is to rest. - To support by some solid foundation; to place
something underneath for support.
Meaning of 'underpin' (Princeton's WordNet)
1 . underpin
[ v]
Meaning (1): - support with evidence or authority or make more certain or confirm
Example in sentence:
The stories and claims were born out by the evidence