1. lowest support of a structure
e.g. it was built on a base of solid rock
he stood at the foot of the tower
Synonym: foundationbasefootgroundworksubstructureunderstructure
2. the fleshy part of the human body that you sit on
e.g. he deserves a good kick in the butt
are you going to sit on your fanny and do nothing?
Synonym: buttocksnatesarsebuttbacksidebumbunscanhindquartershind endkeisterposteriorpratrearrear endrumpsternseattailtail endtooshietushbottombehindderrierefannyass
3. the fundamental assumptions from which something is begun or developed or calculated or explained
e.g. the whole argument rested on a basis of conjecture