NOUN (1)

1. the state of being rancid; having a rancid scent or flavor (as of old cooking oil);

The Collaborative International Dictionary of English v.0.48:

Rancidity \Ran*cid"i*ty\ (r[a^]n*s[i^]d"[i^]*t[y^]), n. [Cf. F.
   rancidit['e].]
   The quality or state of being rancid; a rancid scent or
   flavor, as of old oil. --Ure.
   [1913 Webster]