Cougarboard. So, I decided to figure out which came first.
Going from memory of what I read, it's pretty close to around the same time. I think the term for older woman seeking younger men came along about the year 2000, IIRC.
But the term didn't really take off, at least from what I recall, till that stupid show Cougar Town (no offense Abed) came along, which was 2009.