when you pick up a hot guy in a bar, your sizzling HOT!. intr.v. siz·zled, siz·zling, siz·zles. 1. To make the hissing sound characteristic of frying fat. 2. To seethe with anger or indignation. 3. To be very hot: a summer day. Sizzling definition, to make a hissing sound, as in frying or burning. Informal. to be very hot: to sizzle steaks on the grill; The sun sizzles the pavement. noun.