expression, ichidan verb
tilt one's head in puzzlement; be puzzled
Describes the physical gesture of tilting one's head to the side when confused, doubtful, or questioning something. Often used figuratively to express being puzzled.
彼の説明に、みんな首をかしげた。
Everyone tilted their heads at his explanation.
その話を聞いて、彼女は首
Hearing that story, she tilted her head in puzzlement.