feigned ignorance; pretending not to know
Describes a facial expression or attitude of pretending not to know something, often to avoid involvement or responsibility. Commonly used in the phrase 素知らぬ顔をする.
彼は私の質問に素知らぬ顔をした。
He pretended not to know about my question.
会議で彼女は素知らぬ顔で座っていた。
She sat in the meeting with a look of feigned ignorance.
Standard kanji spelling; 素知らぬ is a fixed phrase meaning 'pretending not to know'.
Variant spelling with そ in kana; less common but still encountered.
All-kana spelling; used for clarity or in informal writing.
The phrase combines 素 (here meaning 'plain' or 'unaffected') with the negative form 知らぬ (archaic/formal negative of 知る, 'to know') and 顔 ('face'). The exact origin is uncertain, but it likely developed as a set expression for a blank or innocent-looking face that hides knowledge.