1. [syn: bottom, underside, undersurface]
The Collaborative International Dictionary of English v.0.48:
Underside \Un"der*side`\, n.
The lower or lowest side of anything. --Paley.
WordNet (r) 3.0 (2006):
n 1: the lower side of anything [syn: bottom, underside,
Moby Thesaurus II by Grady Ward, 1.0:
21 Moby Thesaurus words for "underside":
bed, bedrock, belly, bottom, bottom side, breech, buttocks,
downside, fundament, hardpan, lower side, lowest layer,
lowest level, nether side, nethermost level, rock bottom, sole,
substratum, underbelly, underlayer, underneath