Dictionary.com Unabridged (v 1.1) -
Pronunciation[ek-si-juhn-see, ig-zij-uhn-]
–noun, plural -cies.

1. exigent state or character; urgency.
2. Usually, exigencies. the need, demand, or requirement intrinsic to a circumstance, condition, etc.: the exigencies of city life.
3. a case or situation that demands prompt action or remedy; emergency: He promised help in any exigency.
Also, ex·i·gence.

[Origin: 1575–85; < ML exigentia. See exigent, -ency]
Synonyms 3. crisis, contingency, plight, strait; predicament, fix, pinch.
Dictionary.com Unabridged (v 1.1)
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2006.
American Heritage Dictionary - ex·i·gen·cy (ek's?-j?n-se, ig-zij'?n-) Pronunciation Key
n. pl. ex·i·gen·cies
The state or quality of requiring much effort or immediate action.
A pressing or urgent situation. See Synonyms at crisis.
Urgent requirements; pressing needs. Often used in the plural.