Fussy definition is fairly elusive. It refers to someone who is extremely choosy and critical. A persnickety individual often pay strict attention to detail and has high standards when it comes to standards and flawlessness. Their meticulousness can be regarded as praiseworthy, but it can also magnify unreasonable censure and avoidable dissatisfaction. Being persnickety is commonly associated with meticulous attention to detail but can also be seen as a type of pedantry.