If you're a pessimist, though, you'd only use it ironically.
What followed was worse than even the most dire pessimist could have envisioned.
No, our main issue is that he is an optimist and I'm a pessimist.
What often is needed in the pessimist's case is not a refutation but an aperient.
Steig's wife once told me he was a pessimist in the short run but an optimist in the long run.
The opposite of a leader is a pessimist.
His was not the classic pessimist's view of the glass half empty; his was the misery of one unsatisfied by a glass nearly full.
Baldwin, who at best is a hardened pessimist, is quite unmoved by his present affluence.
And they say that anyone who thinks otherwise is a pessimist.
Yet his argument is hedged with sufficient caveats that the pessimist could still feel vindicated.
Word Origin and History for pessimist
n.
1820, "one who habitually expects the worst" (Knowles' dictionary, 1835, defines it as "A universal complainer"), from 19c. French pessimiste (see pessimism).