Desperation, n.
Etymology: [L. desperatio: cf. OF. desperation.]
1. The act of despairing or becoming desperate; a giving up of hope. This desperation of success chills all our industry. Hammond.
2. A state of despair, or utter hopeless; abandonment of hope; extreme recklessness; reckless fury. In the desperation of the moment, the officers even tried to cut their way through with their swords. W. Irving.
Shades of meaning
Fernald has no entry of its own for desperation; he lists it under despair.
Where he writes about it:
Despondency relaxes energy and effort and is always attended with sadness or distress; despair may produce a stony calmness, or it may lead to desperation. — from despair
Desperation is energized despair, vigorous in action, reckless of consequences. — from despair