Pernickety Definition Meaning Synonyms Demanding definition is reasonably elusive. It refers to someone who is immensely meticulous and judgmental. A persnickety individual tends to nitpick and has high standards when it comes to standards and perfection. Their fastidious nature can be seen as admirable, but it can also magnify extreme disapproval and unnecessary dissatisfaction. Being persnickety is typically linked to detailed focus on specifics but can also be seen as a form of perfectionism.