noun, noun which may take the genitive case particle 'no'
Formal or literary term for being busy or pressed with affairs. Rare in everyday speech; encountered mainly in older or elevated writing.
怱忙のため、返信が遅れました。
Due to being busy, my reply was delayed.
怱忙の折、お時間をいただき恐縮です。
I apologize for taking your time when you are so busy.