The term 'causes irritation' can be summarized by two crossword solutions: 'galls' and 'RILES'. 'Galls' is a noun that refers to an area of skin that has become hardened and swollen due to irritation or infection. It can also refer to a feeling of annoyance or resentment. 'RILES' is a verb meaning to make someone angry or annoyed. Both words describe the feeling of being irritated or provoked, which is the definition of the term 'causes irritation'.