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.
by thinkingriddles March 4, 2012
Get the Silver Ponytail mug.