Synonyms of the word

compulsory

• adj. Required; obligatory; mandatory.
• adj. Having the power of compulsion; constraining.
• n. Something that is compulsory or required.

mandatory

• adj. Obligatory; required or commanded by authority.
• adj. Of, being or relating to a mandate.
• n. (dated, rare) A person, organisation or state who receives a mandate; a mandatary.

obligatory

• adj. Imposing obligation, morally or legally; binding.
• adj. Requiring a matter or obligation.

required

• v. simple past tense and past participle of require.
• adj. Necessary; obligatory; mandatory.