The Collaborative International Dictionary of English v.0.48:

Exigency \Ex"i*gen*cy\, n.; pl. Exigencies. [LL. exigentia:
   cf. F. exigence.]
   The state of being exigent; urgent or exacting want; pressing
   necessity or distress; need; a case demanding immediate
   action, supply, or remedy; as, an unforeseen exigency. "The
   present exigency of his affairs." --Ludlow.

   Syn: Demand; urgency; distress; pressure; emergency;
        necessity; crisis.
        [1913 Webster]