An ass which is only good when viewed in a container, such as jeans. Otherwise it is a big old jiggly ass.
by Deaoay Omtay September 27, 2007
Container ass is used to describe an ass that only looks good because of the pants being worn. The definition works two ways in that the ass only looks good when in a container (pants) and the pants contain(h)er ass.
by www.analdoesntcount.com October 10, 2007