Pronunciation: (man'du-tôr"ē, -tōr"ē), [key]
—adj., n., pl. -ries.
1. authoritatively ordered; obligatory; compulsory: It is mandatory that all students take two years of math.
2. pertaining to, of the nature of, or containing a command.
3. Law.permitting no option; not to be disregarded or modified: a mandatory clause.
4. having received a mandate, as a nation.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.