Green’s Dictionary of Slang

(US) a moaner, a complainer.

[1837		‘Nights At Sea’ in Bentley’s Misc. June 627: Then I’ll be d---d if I don’t [...] and so, ould crusty-gripes, here goes].
1937		AS XII 315/2: Radio lacks a word to describe the disgruntled listener [...] Griper is not precise enough.
c.1943		‘Bill O. Lading’ You Chirped a Chinful!! n.p.: Griper: Always complaining.
1962		Ragen & Finston World’s Toughest Prison 802: gripster – A chronic inmate complainer.
1967–8		Baker et al. CUSS 129: Griper Constantly complaining and irritable.
2006		P. Shannon Davey Darling 56: I felt like a complete gripper. Appleby was lapping this up, grinning from ear to ear.