Another word for indispensable
indispensable essential necessary needful requisiteSearch Thesaurus
These adjectives indicate a pressing need: foods indispensable to good nutrition; funds essential to completing the project; necessary tools and materials; provided them with all things needful; lacking the requisite qualifications.
Another word for indispensableadjective
Incapable of being dispensed with:essential, necessary, needful, required, requisite. See important, necessary