Persnickety means extremely particular about small details, often to the point of being fussy or hard to please. A persnickety eater might refuse to eat a sandwich if the crusts aren't cut off perfectly, or complain if the cheese touches the lettuce. A persnickety teacher might mark down an assignment because the margins are slightly wrong, even if the content is excellent.

The word captures a specific kind of fussiness: caring intensely about things most people consider minor. Someone persnickety about their desk might spend ten minutes arranging pencils in perfect parallel lines. A persnickety reader might abandon a book because they don't like how the author uses commas.

While being careful about details can be valuable, especially in fields like engineering or medicine, being too persnickety can make life harder for yourself and others. The persnickety kid who won't play unless everyone follows their exact rules might find that fewer friends want to play with them. There's a difference between having standards and being so particular that nothing ever feels quite right.

The word sounds a bit old-fashioned and quirky, which fits its meaning: it describes people who seem overly concerned with peculiar little preferences that don't really matter much in the grand scheme of things.