THESAURUS
underlie
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
ROGET THESAURUS
underlie
Lowness
VB
be low, lie low, lie flat,
underlie, crouch, slouch, wallow, grovel, lower.
Implication
VB
be latent, lurk, smolder,
underlie, make no sign, escape observation, escape detection, escape recognition, lie hid, laugh in one's sleeve, keep back, involve, imply, understand, allude to, infer, leave an inference, entail, whisper, read between the lines.