Metaphorical Irritant is a term used to describe something that causes annoyance or frustration, but in a figurative sense. A common example of this is the phrase 'THORN in one's side', which is used to describe an ongoing problem or issue that is difficult to resolve. The crossword solution for this term is THORN, which is a five-letter word that can be used to symbolize this type of metaphorical irritant.