Persnickety is a word used to describe someone who is overly particular, fussy, or finicky about details. Some synonyms for persnickety are fastidious, meticulous, nitpicky, exacting, particular, and picky. These words all indicate someone who has an attention to detail and a preference for things being done in a precise way. Other similar words might include punctilious, scrupulous, and pedantic. Each of these words suggests someone who is concerned with the details of a task, but also implies a certain level of rigidity or inflexibility. Being persnickety can be useful in some situations, but it can also be frustrating for others who work with or for a persnickety person.