optional
adjective uk/ˈɒp.ʃən.əl/ us/ˈɑːp.ʃən.əl/
B2 可选择的;非强制的
If something is optional, you can choose if you want to do it, pay it, buy it, etc.
English is compulsory for all students, but art and music are optional. 英语是所有学生的必修课，而艺术和音乐则是选修的。
Opposites: compulsorymandatory obligatory
- More examples
- Seat-belts are included as standard but electric windows are an optional extra.
- My phone came with 20 optional ringtones.
- Do come to the party - fancy dress is optional.
- There are several optional tours, for which there will be a small charge.
- The basic model is quite cheap, but there are a lot of optional extras.