How to say "elective" in Japanese

• 随意ずいいCommon
  na-adjective, nounCovers 'elective' in the sense of voluntary or optional — something left to each person's own choice rather than being required. Typical of participation, enrollment, or purchases that one is free to make or decline.
  随意ずいいに退席たいせきしてかまいません。↗

  You may leave your seat at will.
• 待機的たいきてき
  na-adjectiveA less common word for 'elective' in the medical sense: procedures or treatment scheduled in advance because they are not emergencies. Outside medical contexts it is seldom the word you want for 'elective'.

Use 随意 for the general sense of 'elective' as voluntary or optional, left to individual choice; 待機的 is a less common term for the medical sense of 'elective', procedures planned in advance rather than emergencies.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• 随意ずいいvoluntary
• 待機的たいきてきelective