Necessity is what is strictly necessary, i.e, that it is indispensable, that it is useful, that one cannot not have or be.
Necessity is a feminine noun that names what is inevitable, indispensable, fundamental, which has great importance, which must be done or fulfilled by action, imposition or obligation.
feel the need it is needing something, it is lacking, it is missing what is necessary or what is indispensable for life or to obtain the means to preserve it. Feeling the need is what is absolutely constraining.
the needy he is the one who suffers the deprivation of the goods necessary to maintain himself. "The extreme need" is the situation of indigence, of begging, is precision, poverty, destitution and misery.
need is a popular expression used to name the functions that are performed by the excretory system.
Economic need is the feeling that leads the individual to withdraw from the external environment his own resources to preserve his life and raise its level.