Fussy definition is fairly elusive. It refers to someone who is vitally particular and fault-finding. A persnickety individual usually pay strict attention to detail and has high standards when it comes to standards and excellence. Their attention to detail can be viewed as laudable, but it can also exacerbate unwarranted disapproval and avoidable dissatisfaction. Being persnickety is typically associated with thorough attention to detail but can also be seen as a type of pedantry.