Pronunciation: (ran'sid), [key]
1. having a rank, unpleasant, stale smell or taste, as through decomposition, esp. of fats or oils: rancid butter.
2. (of an odor or taste) rank, unpleasant, and stale: a rancid smell.
3. offensive or nasty; disagreeable.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.