GYBooker 

A person who is a member of thegybook.com.

"Goodnight GYBookers!"

GYBooker by TheGYBook August 20, 2012

Gymbooker 

A person who updates their facebook status to let their friends know that they are going to, or have been to, the gym. This is done in an attempt to make yourself look big and strong, and therefore gain friends. However, it normally makes you look like a dick.

John (Status) "What an intense workout that was!"

Comment: You're not impressing anybody, gymbooker.

Gymbooker by Joanne Kard April 19, 2011