Despondent, despairing, desperate, hopeless, forlorn mean having lost all or practically all hope.
The same distinctions in implications and connotations are to be found in their corresponding nouns despondency, despair, desperation, hopelessness, forlornness when they denote the state or feeling of a person who has lost hope.
Despondent and despondency imply disheartenment or deep dejection arising out of a conviction that there is no longer any justification of hope or that further efforts are useless.
Despairing and despair imply sometimes the passing of hope, sometimes the utter loss of hope, and often accompanying despondency.
Desperate and desperation imply despair but not the cessation of effort; rather, they often suggest violence and recklessness as a last resource especially in the face of anticipated defeat or frustration.
Hopeless and hopelessness imply both the complete loss of hope and the cessation of effort. The words do not necessarily suggest despondency, dejection, or gloom, for sometimes they imply acceptance or resignation.
Forlorn (see also ALONE 1) and forlornness stress utter hopelessness, but they differ from hopeless and hopelessness in implying hopelessness even in the act of undertaking something because its failure is all but certain.
Desperate, hopeless, and forlorn and their corresponding nouns are applicable not only to men, their moods, words, and acts, but to the things which make men despairing or hopeless.