differential(redirected from a differential)
slang The buttocks. This term comes from the "differential gear" found in motor vehicles. Wow, he's got a great differential—he must work out!
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
n. the buttocks; the rear (end). (From the name of the device that joins the axle to the driveshaft in motorized vehicles.) You’re walking like there’s something wrong with your differential.
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.