← 単語を見るに戻るoptionaladjective#21,246訳語オプショナルオプショナル随意ずいい任意にんい選択的せんたくてき英語の定義possible but not necessary例文An air conditioner is available as an optional extra.The word "the" is optional in this sentence.似ている単語optionalsoptionallyoptionoptionsoperationaloptioned← kravitzpasswords →