1. (adv.) Beneath; below; in a lower place; under; as, a channel underneath the soil.

2. (prep.) Under; beneath; below.

bed bedrock belly below beneath bottom bottom side breech buttocks clandestine covert downside fundament furtive hardpan hole-and-corner lower side lowest layer lowest level neath nether side nethermost level rock bottom sole stealthy subordinate to substratum surreptitious under under-the-table underbelly undercover underlayer underside