Heather
This flower name was one of the most popular in her class in the seventies and eighties (in the 1989 movie Heathers, every snobby girl in the high school clique bore that name), but now, though still pretty and evocative of the Scottish moors, it's beginning to feel as dusty as a bouquet of dried flowers; in 2009, it fell more than 70 places to number 558.
