Webster's Revised Unabridged Dictionary · 1913

Underneath

Underneath , adverb

[Old English undirnepe. See Under, and Beneath.]

Beneath; below; in a lower place; under; as, a channel underneath the soil.
Or sullen mole, that runneth underneath. — Milton

Underneath , preposition

Under; beneath; below.
Underneath this stone lie As much beauty as could die. — B. Jonson