pessimist
US /ˈpes.ə.mɪst/
UK /ˈpes.ə.mɪst/

1.
悲観主義者
a person who tends to see the worst aspect of things or believe that the worst will happen
:
•
He's such a pessimist; he always expects things to go wrong.
彼は本当に悲観主義者だ。いつも物事がうまくいかないと思っている。
•
Don't listen to that old pessimist; things will work out.
あの老いた悲観主義者の言うことを聞くな。物事はうまくいくさ。