Be the foundation or cause (8)
I believe the answer is:
underlie
(Other definitions for underlie that I've seen before include "Be subject to" , "Form the base for" , "Prove to be base" , "Be the basis of" , "Be situated below" .)
I believe the answer is:
underlie
(Other definitions for underlie that I've seen before include "Be subject to" , "Form the base for" , "Prove to be base" , "Be the basis of" , "Be situated below" .)