An uncommon condition in which a naruto fan gets addicted to the TV show Naruto, It usually gets worser day by day to the point trying to convert someone into a narutard by force. A narutard is a person who has narutosis. It is caused by an abnormal mutations of naruto fans cells.
DUDE YOU ACTING LIKE YOU HAVE NARUTOSIS
Narutard : DATTEBAYO!