it's slang term used in the later half of the 20th Century for a gorgeous person who is famous at the time.
1. when a young guy joined up at the Navy recruiter office (next to the Godfather's Pizza - pizza you can't refuse!) he posed under a large poster of Farrah Fawcet to get a snapshot taken. The poster showed her facing forward wearing a bikini! We all called her a 20th Century Foxy.

2. Carmen Electra, Cindy Crawford, Paulina Porizkova, Heather Locklear, all these chicks and more are 20th Century Foxies.
by I Saw U2 Live Twice June 27, 2009
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