pert; tomboyish; lively; impudent
Describes a young girl or woman who is spirited, forward, and somewhat cheeky in a charming way. Often used for a tomboyish or lively personality, sometimes with a hint of impudence.
She's been a tomboy since she was little and often played with the boys.
あの子はおきゃんだけど、憎めない性格だ。
That girl is pert, but you can't help liking her.