REQUIRED Synonyms: 95 Similar and Opposite Words - Merriam-We…
https://www.merriam-webster.com/thesaurus/required
Synonyms for REQUIRED: mandatory, necessary, compulsory, incumbent, needed, urgent, obligatory, imperative; Antonyms of REQUIRED: optional, voluntary, elective, …
DA: 80 PA: 19 MOZ Rank: 17