いないいないばあ

interjection

peek-a-boo!

A phrase used when playing peek-a-boo with a baby; said while hiding and then revealing one's face.

• 赤あかちゃんに「いないいないばあ」をすると、大おお喜よろこびした。

  When I played peek-a-boo with the baby, she was delighted.