3 文書を見つけるための辞書。

• optional
• 随意的, 任意
• possible but not necessary; left to personal choice
• 可能であるが、必要でない

• voluntary
• 自発的, 随意, 随意的, 自主的, 任意
• of your own free will or design; done by choice; not forced or compelled; "man is a voluntary agent"; "participation was voluntary"; "voluntary manslaughter"; "voluntary generosity in times of disaster"; "voluntary social workers"; "a voluntary confession"
• 自分の自由意思または計画で

• voluntarily
• 随意的, 自発的に
• out of your own free will; "he voluntarily submitted to the fingerprinting"
• 自分の自由意思の外で