noun

1. zero; 0; nought; nil (〇 used with kanji numerals)
2. usually kana nothing; zilch

noun

1. circle (sometimes used for zero)
2. "correct"; "good" (when marking a test, homework, etc.)
3. period; full stop
4. handakuten (diacritic)

?

5. *; _ (placeholder used to censor individual characters or indicate a space to be filled in)