often; frequently; again and again
Used to describe actions or events that happen repeatedly over time. Slightly more emphatic than よく or たびたび, and can carry a nuance of 'time and again'.
He is often late.
I apologize for contacting you repeatedly.
Kana spelling is sometimes used for clarity or in informal writing.
Less common variant without the repetition mark; still encountered.
Reduplication of 再 (さい, 'again'), emphasizing repetition. The form 再々 is a straightforward doubling of the kanji.