na-adjective, noun
frivolous; flippant; superficial; shallow; insincere
Describes a person, attitude, or remark that lacks seriousness, depth, or sincerity; often carries a negative judgment.
彼の軽薄な態度に腹が立った。
I was annoyed by his flippant attitude.
軽薄な言葉で人を傷つけてはいけない。
You shouldn't hurt people with shallow words.
彼女は見かけは軽薄そうだが、実はとても真面目だ。
She looks frivolous, but she's actually very serious.