形容词

1. 必不可少的;不可或缺的
If you say that someone or something is indispensable, you mean that they are absolutely essential and other people or things cannot function without them.

1. unavoidable

e.g. the routine but indispensable ceremonies of state

2. not to be dispensed with
essential

e.g. foods indispensable to good nutrition

3. absolutely necessary
vitally necessary

e.g. essential tools and materials
funds essential to the completion of the project
an indispensable worker

Synonym: essential