| 词汇 | thesaurus_not-obligatory |
| 释义 | not obligatoryadjective These are words and phrases related to not obligatory. Click on any word or phrase to go to its thesaurus page. ELECTIVESynonymselective optional not required voluntary selective discretionary open to choice Antonymsrequired obligatory necessary |
反思网英语在线翻译词典收录了377474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。