Obligatory; unavoidable: the routine but indispensable ceremonies of state. (adjective)
One that is indispensable.(noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "indispensable" in a sentence
"The importance of The Living Age to every American reader, as the only satisfactorily fresh and ~COMPLETE~ compilation of an indispensable current literature, -- _indispensable_ because it embraces the productions of"
"The measure, which he described as indispensable to implement reforms more effectively, is Medvedev's first major proposal to amend the Russian Constitution."
"He expressed his great dread of her catching cold, and having a relapse in consequence; but she firmly replied, that she never feared any evil when she was performing a sacred religious duty; that God was too wise and too good to permit one of his creatures to suffer, when in the act of obeying his commands; and she urged so many pious reasons to shew the necessity of her not delaying to perform what she termed her indispensable duty, that my father silently, but very reluctantly, submitted to her decision."