essential
UK: ɪˈsen.ʃəl | US: ɪˈsen.ʃəl
adj. absolutely necessary; extremely important
adj. relating to the basic nature of something; fundamental
n. (usually essentials) a thing that is absolutely necessary
The word essential traces back to the Latin essentialis, derived from essentia ("being, essence"), which itself comes from esse ("to be"). The root essen reflects the core idea of existence or intrinsic nature, while -tial is an adjectival suffix indicating relational quality. Over time, essential evolved from philosophical contexts (referring to the "essence" of things) to its modern sense of "indispensable" or "fundamental."
Water is essential for human survival.
The essential ingredients for this recipe are flour and eggs.
She outlined the essentials of the project in the first meeting.
Good communication is essential in a healthy relationship.
The book covers the essential principles of economics.