Cougar

Noun

 * 1) A mountain lion; Puma concolor.
 * 2)  A woman of middle age who actively seeks the casual, often sexual, companionship of younger males, typically less than 35 years old; by implication a “sexual predator”.

Synonyms

 * catamount, catamountain, mountain lion, painter, panther, puma
 * MILF, older woman