mandatory
Noun · AdjectiveWordNet 3.0
Noun (2)
Adjective (1)
- required by rule“in most schools physical education is compulsory”“attendance is mandatory”“required reading”Synonyms: compulsoryrequired
Webster's Dictionary (GCIDE)
Mandatory \Man"da*to*ry\, a. [L. mandatorius.]
1.Containing a command; preceptive; directory. [1913 Webster]
2.Obligatory; compulsory; required by authority. [PJC]
3.(Law) Not optional; not able to be modified or disregarded; as, seven mandatory clauses in the contract. [PJC]