imperative

Synonyms: acute burning clamant clamorous compulsory critical crucial crying essential exigent immediate important importunate indispensable inescapable insistent instant no turning back obligatory pressing urgent vital

Antonyms: inessential optional secondary unnecessary voluntary

Synonyms: aggressive autocratic bidding bossy commanding dictatorial dominant domineering harsh high-handed imperial imperious ordering overbearing peremptory powerful stern

Antonyms: discretionary free unrestrained voluntary