<p><strong>Adjective</strong></p><ul><li>authoritatively ordered; obligatory; compulsory: It is mandatory that all students take two years of math.</li><li>pertaining to, of the nature of, or containing a command.</li><li>Law: permitting no option; not to be disregarded or modified: a mandatory clause.</li><li>having received a mandate, as a nation.</li></ul><p><strong>Noun</strong></p><ul><li>plural: mandatories.</li><li>mandatary.</li></ul>