rancid

adjectives

(used of decomposing oils or fats) having a rank smell or taste usually due to a chemical change or decomposition
"rancid butter"; "rancid bacon"
rancid
is derived from
rancidness
is similar to
lacking freshness, palatability, or showing deterioration from age
"stale bread"; "the beer was stale"
stale
smelling of fermentation or staleness
rancid, sour
is derived from
rancidness
is derived from
rancidity