requisite
re-qui-site
noun
An essential or necessary thing required for a specific purpose.
"Patience is a requisite for good teaching."
adjective
Absolutely necessary or essential for a particular purpose or outcome.
"Punctuality is a requisite quality for this role."
Thesaurus
Synonyms: needed, necessary, required, needful, necessity, essential, requirement
Antonyms: inessential, nonessential