sour face; wry face
Describes a facial expression showing displeasure, bitterness, or discomfort, often in reaction to something unpleasant.
He listened to the news with a sour face.
The child made a wry face after taking the bad-tasting medicine.
Compound of 苦り (にがり, nominalized form of 苦る 'to feel bitter') + 顔 (かお 'face'). The exact derivation of 苦る is uncertain, but it is related to 苦い (にがい 'bitter').