expression, godan verb (-ru)
nitpick; split hairs; complain about trifles
Idiomatic expression literally meaning 'to pick at the corners of a tiered food box with a toothpick'; used to describe someone who fusses over trivial details or finds fault in minor things. Often used in negative contexts to criticize overly meticulous or petty behavior.
See also: 重箱の隅をつつく
He always says things that are just nitpicking.
そんな重箱の隅をようじでほじくるような指摘はやめてください。
Please stop making such nitpicky remarks.