聞ききかじる

godan verb (-ru), transitive verb

have a smattering of knowledge; know a little about

Implies superficial, second-hand knowledge picked up by hearing bits and pieces, not thorough study. Often used humbly or critically.

• 彼かれは経けい済ざい学がくを聞ききかじっているだけだ。

  He only has a smattering of economics.

• 聞ききかじった知ち識しきで議ぎ論ろんしないほうがいい。

  You shouldn't argue based on half-baked knowledge.