necessity

[1]	requirement , essential , necessary , requisite , need , prerequisite , basic , fundamental , desideratum , constraint
[2]	indispensability , essential , requirement , unavoidability , needfulness , requisite , necessary , inexorability
[3]	poverty , want , indigence , need , destitution , penury , straits , difficulty , difficulties , pauperism , neediness
[4]	urgency , emergency , crisis , misfortune , exigency , pinch , extreme , matter of life and death