Indispensable
Indispensable is an adjective that describes something or someone absolutely necessary; it denotes that something cannot be dispensed with in a given context. Objects, skills, people, or conditions described as indispensable are considered essential to achieving a goal, ensuring safety, or maintaining function. In common usage, the term often carries a strong positive appraisal, highlighting critical importance rather than mere usefulness.
Etymology: The form is built from the prefix in- meaning not, added to dispensable, yielding “not to
Usage notes: Indispensable is typically reserved for highly important items, roles, or concepts. It coexists with