| 词汇 | thesaurus_optional |
| 语种 | 英语、汉语、英汉翻译、汉英翻译 |
| 释义 | optionaladjective These are words and phrases related to optional. Click on any word or phrase to go to its thesaurus page. Or, go to the definition of optional. The car comes with a heater but air conditioning is optional. Synonymsleft to one's choice individually decided elective voluntary nonobligatory not required volitional unforced discretionary discretional available at additional cost open-ended open allowable Antonymsmandatory obligatory required compulsory |
体育网英语在线翻译词典收录了466383条英语词汇在线翻译词条，基本涵盖了全部常用英语词汇的中英文双语翻译及用法，是英语学习的有利工具。