プログレッシブ和英中辞典(第３版)の解説
ずいい【随意】
随意の｜〔選択が自由の〕optional; 〔自発的な〕voluntary
- 寄付は随意である
Contributions are voluntary. - 今切符を買うか買わぬかはご随意に
It's up to you whether you buy a ticket now or not. - 彼の随意にさせてあげなさい
Let him do as he pleases.／Let him have his way. - ここにある物はご随意にお使いください
These things are at your disposal.
随意科目｜((米)) an elective (course) ，((英)) an optional subject