This is the 4905th most frequent Japanese word.
疑問符
Question mark.
In this context, '疑問符' metaphorically implies something questionable or uncertain.
彼女の答えには疑問符が付く。
Her answer is questionable.
Here, '疑問符' refers literally to the question mark punctuation.
疑問符は質問文の最後に置かれます。
Question marks are placed at the end of interrogative sentences.
Here, '疑問符' serves as a metaphor for arising doubts or uncertainties.