curmudgeon
/kərˈmʌdʒən/
noun
- A person who is often bad-tempered, grumpy, and difficult to please, especially an older person.
- Despite being a famous curmudgeon, he secretly donated money to the local library.
- Don't be such a curmudgeon — try to enjoy the party!
- The old curmudgeon next door always complains about the children playing in the street.