WordNet sense 1 (a space reserved for sitting (as in a theater or on a train or airplane)):

place

WordNet sense 2 (the fleshy part of the human body that you sit on):

backside, behind, bottom, bum, buns, buttocks, can, derriere, fanny, hindquarters, posterior, rear, rump, stern, tail, tush, arse, fundament, keister, nates, prat, tooshie, tush, tail end, hind end

WordNet sense 3 (place ceremoniously or formally in an office or position):

induct, invest

WordNet sense 4 (show to a seat; assign a seat for):

sit, sit down