Other forms: unappetizingly
Anything unappetizing either looks like it would taste terrible or is otherwise unattractive. If the school cafeteria offers only unappetizing mystery meat and limp salad, you'll probably decide to bring a sandwich for lunch.
Your personal list of unappetizing things might include black licorice, brussels sprouts, and egg salad. You can also use this adjective for other things that leave you feeling a little queasy, like a relative's unappetizing political convictions or an unappetizing scene in a horror movie that makes you cover your eyes. Unappetizing is what you get when you add the "not" prefix un- to appetizing, which stems from the Latin appetitus, "desiring toward."