40 entries under adjective topic. ×
| compulsory(forced, binding) | |
| required(verb, voluntary, forced) | |
| forced | |
| indispensable | |
| necessary | |
| obligatory(essential, required) | |
| mandatory(necessary, required) | |
| automatic | |
| essential | |
| prerequisite(secondary, necessary) | |
| basic | |
| imperative | |
| inevitable | |
| involuntary | |
| unavoidable | |
| peremptory | |
| actual | |
| binding | |
| central | |
| certain |
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| APA | Smart Define. (2015). optional thesaurus. Retrieved September 22, 2026, from https://smartdefine.org/optional/thesaurus/antonyms |
| Chicago | Smart Define. 2015. "optional thesaurus" https://smartdefine.org/optional/thesaurus/antonyms (accessed September 22, 2026). |
| Harvard | Smart Define 2015, optional thesaurus, Smart Define, viewed 22 September, 2026, <https://smartdefine.org/optional/thesaurus/antonyms>. |
| MLA | Smart Define. "optional thesaurus" 14 April 2015. Web. 22 September 2026. <https://smartdefine.org/optional/thesaurus/antonyms> |