Such as must be; impossible to be otherwise; not to be avoided; inevitable.
source: Webster 1913
noun
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.
source: WordNet 3.0
A thing that is necessary or indispensable to some purpose; something that one can not do without; a requisite; an essential; -- used chiefly in the plural; as, the necessaries of life.
