Bonetail 

(n) the nickname you give your significant other when they have tailbone thats a little longer than normal.

I love my bonetail!

Bonetail by BooBear?Mofucka August 23, 2009

bonytail 

A ponytail on a balding man. It can be viewed as a bad cross pollination between an ultimullet and a skullet. Very popular hairstyle in the 1980's.

Also, it is a species of endangered fish (Gila elegans). It is a rare minnow found in the Colorado River.

My bald old man has a bonytail down to his fatass.

bonytail by The 80's rock! June 11, 2006

bonytail 

A girl with no booty where her pants can barely stay on without the assistance of a belt.

The kind of bonytail that you don't bounching on your cock because it will be like fucking a wall

bonytail by KBCA February 12, 2007