desolate (adj.)

mid-14c., "without companions," also "uninhabited," from Latin desolatus, past participle of desolare "leave alone, desert," from de- "completely" (see de-) + solare "make lonely," from solus "alone" (see sole (adj.)). Sense of "joyless" is 15c.

desolate (v.)

late 14c., from desolate (adj.). Related: Desolated; desolating.