a "blank insult" is the ultimate way to add extra punch to an insult
what you do is make up a random word that sounds like it's an insult, and when the victim asks what it is, you make up a definition that directly insults the person you're roasting
(slicer is the blank insult in this scenario)
guy 1: "you look like a retard"
guy 2: "you look like a fucking slicer"
guy 1: "wtf is a slicer"
guy 2: "a slicer is some 4 eyed short gay kid"
guy 1: "damn"