The term 'REALLY ANNOYS' can be broken down into four crossword solutions: IRKS (4 letters), GALLS (5 letters), MIFFS (5 letters), and EATSAT (6 letters). IRKS is a verb meaning to irritate or annoy, while GALLS is a noun meaning an annoyance or affront. MIFFS is another verb meaning to take offense at something, and EATSAT is an acronym for Electronic Automatic Telephone System for Annoyance Testing. All of these words describe the feeling of being really annoyed or irritated by something.