adj. (rottener, rottenest) 1 rotting or rotted; falling to pieces or liable to break or tear from age or use. 2 morally, socially, or politically corrupt. 3 sl. a disagreeable, unpleasant (had a rotten time). b (of a plan etc.) ill-advised, unsatisfactory (a rotten idea). c disagreeably ill (feel rotten today). rotten borough hist. (before 1832) an English borough able to elect an MP though having very few voters. rotten-stone decomposed siliceous limestone used as a powder for polishing metals. rottenly adv. rottenness n.
[ ME f. ON rotinn, rel. to ROT, RET ]