indispensable
adj.adj. something or someone that is so important that you cannot do without them. It describes a person or tool that is completely necessary for a job or situation.
adj. absolutely necessary or essential; impossible to replace or do without. Often used to describe human capital or critical infrastructure within a system.
A good dictionary is indispensable for language learners.
Her deep knowledge of the local market made her an indispensable member of the international sales team.
While individual components may seem minor, the specialized software remains indispensable to the integrity of the entire security network, as no viable alternative currently exists.
Borrowed from Middle French indispensable, from Medieval Latin indispensābilis, corresponding to in- + dispensable.
Typically follows a linking verb or precedes the noun it modifies; frequently paired with the preposition 'to'.
an indispensable tool for the joban indispensable tool to the jobWhile 'for' is common, 'indispensable to' is the standard collocation when describing necessity within a specific system or process.