noun
Derogatory term for a child, often used to scold or belittle. Carries a rough, old-fashioned, or dialectal feel.
このわっぱが、またいたずらをしたな。
This brat has been up to mischief again, huh.
わっぱのくせに生意気だ。
You're just a kid, but you're so cheeky.
Also derogatory for a boy, but わっぱ is more rustic and less common.
Possibly from 童 (warawa) with sound change; exact derivation uncertain. Used as a derogatory term for children.