compulsory

Adjective

WordNet 3.0

required by rule“in most schools physical education is compulsory”“attendance is mandatory”“required reading”Synonyms: mandatory required

Compulsory \Com*pul"so*ry\, a. [LL. compulsorius.]

1.Having the power of compulsion; constraining. [1913 Webster]

2.Obligatory; enjoined by authority; necessary; due to compulsion. [1913 Webster]

This contribution threatening to fall infinitely short of their hopes, they soon made it compulsory.— Burke.[1913 Webster]