Ob"li*ga*to*ry (?), a. [L. obligatorius: cf.F. obligatoire.]
Binding in law or conscience; imposing duty or obligation; requiring performance or forbearance of some act; -- often followed by on or upon; as, obedience is obligatory on a soldier.
As long as the law is obligatory, so long our obedience is due.
© Webster 1913.