desolationOnline Etymology Dictionary
late 14c., "action of laying waste," also "sorrow, grief," from O.Fr. desolacion (12c.) "desolation, devastation, hopelessness, despair," from Church L. desolationem (nom. desolatio), noun of action from pp. stem of desolare (see desolate). Meaning "condition of being ruined or wasted" is from early 15c. desolate (adj.) Desolate: mid-14c., "without companions," also "uninhabited," from L. desolatus, pp. of desolare "leave alone, desert," from de- "completely" (see de-) + solare "make lonely," from solus "alone" (see sole (adj.)). Sense of "joyless" is 15c. As a verb, from late 14c.