- authoritatively ordered; obligatory; compulsory: It is mandatory that all students take two years of math.
- pertaining to, of the nature of, or containing a command.
- Law. permitting no option; not to be disregarded or modified: a mandatory clause.
- having received a mandate, as a nation.
noun, plural man·da·to·ries.
- having the nature or powers of a mandate
- obligatory; compulsory
- (of a state) having received a mandate over some territory
noun plural -ries
- Also called: mandatary a person or state holding a mandate
adj.1570s, “of the nature of a mandate,” from Late Latin mandatorius “pertaining to a mandator,” from Latin mandatus, past participle of mandare (see mandate (n.)). Sense of “obligatory because commanded” is from 1818.