Definition of indispensable 1 : not subject to being set aside or neglected an indispensable obligation 2 : absolutely necessary : essential an indispensable member of the staff
Indispensable definition, absolutely necessary, essential, or requisite: an indispensable member of the staff. See more.
in′dis·pens′a·bly adv. These adjectives apply to something that cannot be dispensed with: foods that are indispensable to good nutrition; education that is critical to success; funds essential to completing the project; the necessary tools for the job; lacking the requisite qualifications for the position.