1. (v. t.) To be at the basis of; to form the foundation of; to support; as, a doctrine underlying a theory\.

2. (v. t.) To lie under; to rest beneath; to be situated under; as, a stratum of clay underlies the surface gravel.

3. (v. t.) To be subject or amenable to.

4. (v. i.) To lie below or under.

5. (n.) See Underlay, n., 1.

afford support back back up be latent bear bear up bed on bolster bolster up bottom on brace build on buoy up buttress carry couch cradle crawl crouch crutch cushion escape notice found on give support ground on grovel hibernate hold hold up hug the earth keep afloat keep up lend support lie beneath lie dormant lie hid lie low lie prone lie prostrate lie under lurk mainstay maintain make no sign pillow prop reinforce set on shore shore up shoulder smolder squat stay subsidize subvention support sustain underbrace undergird underpin underset upbear uphold upkeep