Derogatory. Someone who suffers from Down's Syndrome (trisomy 21). Derived from contraction of a now unused description: "Mongoloid features" referring to the bridgeless nose and epicanthic folds of certain far-eastern races.
Jesus man, Maccy D's have got a Jimmy no-stars working at the drive thru' and he's a fuckin' mongo.
by Gezza T April 20, 2003