プログレッシブ和英中辞典(第4版)の解説
にんい【任意】
❶〔随意〕(the) option
任意の optional
この科目は取っても取らなくても任意である
This subject is optional [《米》 elective].／You have the choice [option] of taking this subject or not.
この金は任意に使えます
This money is at your disposal [discretion].／You can use this money as you please [like].
任意に解釈してください
You are free to give any interpretation to it you like.
❷〔自発的にすること〕任意の voluntary
任意の寄付
a voluntary donation
任意出頭
警察署に任意出頭を求められた
I was requested to make a voluntary appearance at the police station.
任意捜査
参考人の家宅を任意捜査した
The police searched the house of the witness with his consent.
任意退職
voluntary retirement
任意団体
a private organization neither controlled nor protected by law
任意抽出法
random sampling
任意同行
警察まで任意同行願います
I (must) ask you to come with me to the police station voluntarily [of your own accord].