expression, pre-noun adjectival
innocent-looking; wouldn't hurt a fly
Describes someone who appears so gentle and harmless that they seem incapable of even killing an insect. Often used with a hint of irony or to emphasize a deceptively meek appearance.
彼女は虫も殺さぬ顔で、実はとてもしたたかだ。
She looks as though she wouldn't hurt a fly, but she's actually quite shrewd.
虫も殺さぬような笑顔で近づいてきた。
He approached with an innocent-looking smile.