任意

プログレッシブ和英中辞典(第4版)

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].

出典　小学館「プログレッシブ和英中辞典(第4版)」