pessimist (n.)

1820, "one who habitually expects the worst, one who exaggerates the evils of life, one given to melancholy or depressing views" (Knowles' dictionary, 1835, defines it as "A universal complainer"), from 19c. French pessimiste (see pessimism). Also "one who accepts the metaphysical doctrine of pessimism" (it is difficult to distinguish the senses).