expression, godan verb (-ru)
to cock one's head in puzzlement; to tilt one's head in thought; to think hard
Describes the physical gesture of tilting one's head when puzzled or deep in thought, often implying mental effort or confusion. Can be used literally or figuratively.
彼は難しい問題に首をひねった。
He cocked his head at the difficult problem.
その説明を聞いて、みんな首をひねっ
Hearing that explanation, everyone tilted their heads in puzzlement.