Un"der*let`ter (?), n. A tenant or lessee who grants a lease to
another.
Un`der*lie" (?), v. t. [AS. underlicgan. See Under, and Lie to be
prostrate.] 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.