Older woman, generally mid-30's or above, who attempts to sleep with younger men. Cougars are generally skanky and promiscuous, and therefore likely to have STD's. Their predation is generally due to their inability to secure a permanent relationship with a man their own age (or older), and generally reflects a form of desperation, premised on the usually vain hope that the horny, indiscriminate nature of the younger male will lead to at least temporary companionship. Known for animal prints, heavy makeup, emaciation and/or obesity, and a deluded view of self.
Not to be confused with a MILF, who is an attractive, genuine, healthy, well-preserved older woman over 30 (or 40) who younger men genuinely want to be with. The key difference is that the cougar pursues younger men, generally unsuccessfully, while the MILF is actively desired by men of all ages, but is more likely to already be in a committed relationship, due to her appeal.
That drunk cougar has been all over me all night, and won't leave me alone. Wish that MILF or her hot daughter would step in and run interference for me.