Definition - What does Cougar mean?
A cougar refers to an older woman who seeks sexual relationships with younger men. She is often associated with the MILF (Mother I'd Like to Fuck), although there are differences, mostly based on a woman's level of attractiveness and age. The New York Times' definition is more specific. It states that a cougar needs to be aggressive and older than 40 years old. Some people refer to any older woman who has a relationship with a younger man as a cougar, even when she is not actively seeking sexual attention from others.
Kinkly explains Cougar
There are different versions on the origins of the term “cougar.” It is said to have come from cougardate.com, a Canadian dating site. It may also have come from the Canadian dismissive term for older women who go home with the last pickings of a late-night bar. Of course, there is nothing to be dismissive about older women who know what they want sexually and try to get it. If anything, this can be very liberating and empowering for women of all ages.