cur·mud·geon 
/kɚˈmʌʤən/ noun
plural cur·mud·geons /kɚˈmʌʤən/ noun [count] old-fashioned : a person (especially an old man) who is easily annoyed or angered and who often complains
▪ a lonely old curmudgeon
▪ a lonely old curmudgeon
— cur·mud·geon·ly adjective [more curmudgeonly; most curmudgeonly]
▪ a curmudgeonly [=bad-tempered] old man
▪ a curmudgeonly [=bad-tempered] old man
