Difference Between In and On with Comparison Chart Key ootn meaning is a term used to describe a attire that is worn during the evening or for special occasions. symbolizes love, passion, and romance. Therefore, an ootn showcases an fashionable and alluring attire that reflects the affection for clothing and embraces the evening vibe. Sporting an ootn can boost your confidence, make a statement, and display elegance and charisma. No matter it's a glamorous dress or an chic suit, the ootn ensures that you catch everyone's attention and leave a lasting impression at any evening event.