Squick: Possibly a contraction of "squeamish" and "Ick!" A negative emotional response, more specifically a disturbed or disgusted one.
"Squicky" and "squicked" are also common forms, with this very wiki having apparently invented the form "squicktastic".
Not to be confused with squee, the very opposite. We hope.
Things that make the audience throw up often make the characters throw up as well. We have a whole pile of Disgust Tropes for in-universe squick.