Persnickety definition is quite difficult to understand. It refers to someone who is exceptionally selective and fault-finding. A persnickety individual usually be fastidious and has high standards when it comes to quality and perfection. Their fastidious nature can be seen as admirable, but it can also magnify unwarranted disapproval and avoidable dissatisfaction. Being persnickety is commonly associated with meticulous attention to detail but can also be seen as a manifestation of perfectionism.