Detailed meaning of indispensable Something that is indispensable is considered to be absolutely necessary, and cannot be replaced or done without. For example, a key employee can be considered indispensable to a company, as their skills and contributions are critical to the company's success. indispensable definition : absolutely necessary or essential for a purpose. Check meanings, examples, usage tips, pronunciation, domains, and related words. Discover expressions like "nobody's indispensable ", "make oneself indispensable ", " indispensable as air". The meaning of INDISPENSABLE is absolutely necessary : essential. How to use indispensable in a sentence. Indispensable definition : Absolutely necessary; essential.Formerly a friend and disciple of Mazzini, with whom he had broken on the question of the monarchical form of government which Crispi believed indispensable to the unification of Italy, he had afterwards been one of Garibaldis most efficient coadjutors and an active member of the party of action.