Definition of mandatory adjective from the Oxford Advanced Learner's Dictionary. required by law synonym compulsory. The offence carries a mandatory life sentence. mandatory (for somebody) (to do something) It is mandatory for blood banks to test all donated blood for the virus. Mandatory definition: authoritatively ordered; obligatory; compulsory .. See examples of MANDATORY used in a sentence. The meaning of MANDATORY is required by a law or rule : obligatory . How to use mandatory in a sentence. Did you know? MANDATORY definition: 1. Something that is mandatory must be done, or is demanded by law: 2. Something that is mandatory …. Learn more.
