柯林斯詞典optional /??p??n?l/ 1. ADJ If something is optional, you can choose whether or not you do it or have it. 可選擇的 Sex education is a sensitive area for some parents, and thus it should remain optional. 性教育對一些家長來說是個敏感的話題，因此應該還是非強制性的。 返回 optional劍橋詞典If something is optional, you can choose if you want to do it, pay it, buy it, etc. 可選擇的；非強制的 English is compulsory for all students , but art and music are optional. 英語是所有學生的必修課，而藝術和音樂則是選修的。 例句 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 . 返回 optional