adjective
necessary
Synonyms: appropriate, called for, compulsatory, compulsory, condign, demanded, deserved, due, enforced, essential, imperative, imperious, indispensable, just, mandatory, needed, needful, obligatory, prerequisite, prescribed, recommended, right, rightful, set, suitable, unavoidable, vital
Antonyms: nonessential, optional, unnecessary
noun
necessity, want
Synonyms: claim, compulsion, concern, condition, demand, desideratum, element, engrossment, essential, exaction, exigency, extremity, fulfillment, fundamental, imperative, lack, must, need, obligation, obsession, pinch, precondition, preliminary, preoccupation, prepossession, prerequisite, prescription, provision, proviso, qualification, sine qua non, specification, stipulation, terms, urgency, vital part
Antonyms: desire, option, wish