ex·i·gen·cy /'ek-sə-jən-sē, ik-'si-jən-sē/ n pl -cies
1: that which is required in a particular situation
— usu. used in pl.
2 a: the quality or state of being exigent
b: a state of affairs that makes urgent demands
Merriam-Webster’s Dictionary of Law. Merriam-Webster. 1996.