the condition of being essential or indispensable
"The necessity of oxygen makes life on Earth impossible without it."
anything indispensable
"food and shelter are necessities of life"
"the essentials of the good life"
"allow farmers to buy their requirements under favorable conditions"
"a place where the requisites of water fuel and fodder can be obtained"
The quality or state of being necessary, unavoidable, or absolutely requisite.
"The sudden storm was a clear necessity that forced everyone to seek shelter immediately."
In plain English: Necessity is something you absolutely need to have or do because life doesn't work without it.
"Water is an absolute necessity for all living things to survive."
Usage: Use "necessity" to describe an essential requirement that cannot be avoided rather than simply something needed. It often pairs with phrases like "a matter of necessity" when emphasizing inevitability over mere preference.
The word "necessity" entered English through Middle and Old French as a borrowing from the Latin necessitās, which originally meant unavoidable compulsion or exigency. It is essentially a doublet of the adjective "necessary," sharing the same root meaning but arriving via different linguistic paths.