不痛不癢

1. • lit. doesn't hurt, doesn't tickle (idiom) sth is wrong, but not quite sure what
2. • fig. not getting to any matter of substance
3. • scratching the surface
4. • superficial
5. • perfunctory

Character by character

• 不(bù)no
• 痛(tòng)ache
• 不(bù)no
• 癢(yǎng)itch