Synonyms of rancid

Adjective

1. rancid, stale (vs. fresh)

usage: (used of decomposing oils or fats) having a rank smell or taste usually due to a chemical change or decomposition; "rancid butter"; "rancid bacon"

2. sour, rancid, malodorous (vs. fragrant), malodourous, unpleasant-smelling, ill-smelling, stinky

usage: smelling of fermentation or staleness

Definition and meaning of rancid (Dictionary)