Underlie /(?)/

Un·der·lie

Underlie

v. t.
  1. To lie under; to rest beneath; to be situated under; as, a stratum of clay underlies the surface gravel.
  2. To be at the basis of; to form the foundation of; to support; as, a doctrine underlying a theory.
  3. To be subject or amenable to. [R.]
    The knight of Ivanhoe . . . underlies the challenge of Brian der Bois Guilbert.

Underlie

v. i.
  1. To lie below or under.

Underlie

n.
  1. See Underlay, n., 1.