Well, by modern day definetion. It is an older woman most likely in her 40's that persues younger men around mid 20's and younger usually for sexual gratification. By the way, its not my definition. I didn't make it up pop culture did. By pop culture definition you are not a cougar.
My definition of cougar is a woman in her 40's and up who is either divorced, cheating on her husband, on her 2nd, 3rd, 4th marriage, a milf, or wannabe milf, desperately insecure, miles and baggage on her and her cooter, who seeks younger men, because they are not hip to the mentally unstable fuck ups that these women are. Men see cooter, women see a new test driver. Remember used Ferrari, new owner, who is younger--but hey it's a Ferrari (until you see the maintenance)