Synonyms for indispensable

Adjective

1. indispensable (vs. dispensable), critical, vital, necessary

usage: not to be dispensed with; essential; "foods indispensable to good nutrition"

2. essential, indispensable, necessary (vs. unnecessary)

usage: absolutely necessary; vitally necessary; "essential tools and materials"; "funds essential to the completion of the project"; "an indispensable worker"

3. indispensable, obligatory (vs. optional)

usage: unavoidable; "the routine but indispensable ceremonies of state"