Persnickety is a lively, fancy word for “fussy.” If you’ve sent your salad back to the kitchen three times, you might be a persnickety eater.
The adjective persnickety sounds prickly like a porcupine, and persnickety people can indeed be sharp and prickly when they don’t get things precisely as they wish. I don’t mean to be persnickety about grammar, but you shouldn’t use “ain’t” in an academic paper. If you’re persnickety about your coffee, you’ll probably want to put the cream and sugar in yourself.
Thanks to Vocabulary.com