Etymology From slush + -y. In the sense of a cook, from the sense of slush meaning to refuse grease and fat collected in cooking.
1
Covered in slush.
I can remember, and not that long ago, when slushy mid-winter days like today always lead my feverish imagination down a murky hallway known as "shacking up."1987 February 8, Robert Storen, “On Being Cozy with Mister Right”, in Gay Community News, volume 14, number 29, page 7: