A "pet peeve" is a small thing that bothers someone, like a minor annoyance. There are several synonyms for this phrase, including "irritation," "vexation," "annoyance," and "nuisance." These words convey a sense of mild but persistent annoyance that can be caused by a variety of things, from a noisy neighbor to a cliched phrase. Other synonyms for "pet peeve" might include "bugbear," "niggle," or "chore." Whatever term you use, the idea behind it is the same: something that may not be a big deal in the grand scheme of things, but that nonetheless has the power to get on your nerves from time to time.