WordNet sense 1 (desert (a cause, a country or an army), often in order to join the opposing cause, country, or army):

defect, defect

WordNet sense 2 (located in a dismal or remote area; desolate):

godforsaken, waste, wild

WordNet sense 3 (leave someone who needs or counts on you; leave in the lurch):

abandon, desolate, forsake, desolate