Underpants normally worn by men of the homosexual persuasion, whereby the opening pouch is located at the rear as opposed to the front.
I'm going out speed fudging tonight, so I got me Y Backs on for easy access!
by Dickie Brooks September 21, 2007
1 more definition
Tank top worn by bodybuilders that has two straps in the front and comes together in the back as one strap making a Y appearance.
Travis has a sweet y-back, but Tyler definently fills it out better because he is more huge.
by tommytoughnuts April 23, 2008