Ironic, mood-lightening expression to be used upon bearing witness to an unpleasant shitstain or skidmark.
A prison guard examines an inmate's bed, peeling back the covers to reveal a large brown stain of fecal matter plastered over the sheets. To bring humour and gravitas to the discovery he remarks, "That's not gravy." (As seen on the television documentary 'Strangeways'.)
by AngeloComet May 18, 2011