Definition from Wikipedia should explain that sign for ya.
Cougar is a slang term referring to a woman who seeks sexual relations with considerably younger men. The term does not apply to those woman who have a stable and lasting relationship with their younger partner.[citation needed] Typically, the term refers to women over 40 years old who pursue sexual relations with people more than six years younger.[1] The origin of the word is debated, but it is thought to have originated in Western Canada and first appeared in print on the Canadian dating website Cougardate.com,[2] and has been used in TV series, advertising and film. The 2007 film Cougar Club was dedicated to the subject, and in spring 2009 TV Land aired a reality show called The Cougar. The sitcom Cougar Town originally explored the difficulty and stigma of many so-called “cougars”.