underneath
adv. place B1 Intermediate US //ˌəndɝˈniθ// UK //ˌʌndənˈiːθ// un·der·neath
adv. directly below or under something else. You use it to describe where something is hidden or covered by another object.
adv. situated directly below or beneath something else, often so as to be covered or hidden by it.
The cat is hiding underneath.
The floorboards looked old, but the original hardwood was still in perfect condition underneath.
The surface of the lake appeared calm, but a powerful current was moving dangerously underneath.
From Middle English undernethe, undernethen, from Old English underneoþan (“underneath”), ultimately from Proto-Germanic *underniþer. Equivalent to under- + neath.
Usage
As an adverb, it typically appears at the end of a clause or immediately after the verb it modifies.