1. Someone who was a
hippie in the 1960s that grew up but kept their hair long because at
heart they are still hippies. Many of them can be found in the academic world.
2. A 1960s revolutionary radical who didn't
cut their hair because for them the revolution is still on. They are older, wiser, and more dangerous.
Def 1. Tonight we're gonna be chillin' some the
silver ponytails, bring lots of weed.
Def 2. The
silver ponytails won't rest until they bring down the whole American
system.