Nouns

(n)bottom, underside, undersurfacethe lower side of anything
(n)bottomthe lowest part of anything“they started at the bottom of the hill”
(n)buttocks, nates, arse, butt, backside, bum, buns, can, fundament, hindquarters, hind end, keister, posterior, prat, rear, rear end, rump, stern, seat, tail, tail end, tooshie, tush, bottom, behind, derriere, fanny, assthe fleshy part of the human body that you sit on“he deserves a good kick in the butt”, “are you going to sit on your fanny and do nothing?”
(n)bottom, bottom of the inningthe second half of an inning; while the home team is at bat
(n)bed, bottoma depression forming the ground under a body of water“he searched for treasure on the ocean bed”
(n)bottomland, bottomlow-lying alluvial land near a river
(n)bottom, freighter, merchantman, merchant shipa cargo ship“they did much of their overseas trade in foreign bottoms”

Verbs

(v)bottomprovide with a bottom or a seat“bottom the chairs”
(v)bottomstrike the ground, as with a ship's bottom
(v)penetrate, fathom, bottomcome to understand

Adjectives

(a)bottomsituated at the bottom or lowest position“the bottom drawer”
(s)bottomthe lowest rank“bottom member of the class”