Green’s Dictionary of Slang

1. (orig. RAF) a bore.

1922		‘J.H. Ross’ Mint (1955) 42: Someone [...] begins ‘The green eye of the Yellow God’: and carries on unnerved though a dozen storm ‘Binder’ at him.
1930		T.E. Lawrence letter 10 Feb. in Garnett Letters (1938) 679: More books go to you almost at once. You’ll find some of the packets have quite decent things amongst them though generally they are what the troops call my ‘binders’.
1940–1		‘A Hudson Song’ in C.H. Ward-Jackson Airman’s Song Book (1945) 121: Instead of bombing the binder he went out on the spree.
1997		P. Theroux Kowloon Tong 56: Don’t be such a binder, Bunt.

2. a habitual complainer.

1984

Partridge DSUE (8th edn) 80/1: since ca. 1925.