noun
child's face; childlike face
Literal noun use for the face of a child or an innocent, childlike face; in everyday Japanese, 子どもの顔 is more direct when simply saying 'a child's face.'
この画家は、あどけない童顔を描くのが得意だ。
This painter is good at depicting innocent children's faces.
noun, noun which may take the genitive case particle 'no'
Most common for an older child or adult whose face looks younger than their actual age. Often used predicatively as 童顔だ or attributively as 童顔の.
彼は童顔だが、もう三十代だ。
He has a baby face, but he is already in his thirties.
童顔の俳優として人気がある。
He is popular as a baby-faced actor.