Meanings
childish · humorousUsed to taunt someone and express joy over their misfortune, especially if it is the speaker's doing or to their advantage; na-na na-na boo-boo
Hey, das war mein Platz! − Ätschibätschi! Jetzt nicht mehr!Hey, that was my seat! − Na-na na-na boo-boo! Now it's not!