underlie

verb5

1. •
   To lie in a position directly beneath something.
2. •
   To serve as a basis of; form the foundation of.

   • […] she was carved into the bole of a red cedar tree. Sun and storm had bleached the wood, moss here and there softened the crudeness of the modelling; sincerity underlay every stroke. — 1941
3. •
   To lie under or beneath.

   • A stratum of clay underlies the surface gravel.
4. •
   To underlay.
5. •
   To be subject to; be liable to answer, as a charge or challenge.

   • The knight of Ivanhoe […] underlies the challenge of Brian der Bois Guilbert. — 1819