Green’s Dictionary of Slang

bender n.1

[SE bend]

1. in monetary uses [the ease with which the thin metal could be bent; Bee: ‘Bender [...] takes its name from the form, the usual shape of the old coin, which were bent, twice, adversely, presenting the appearance at the edge of the letter (s)’].

(a) [late 18C–1930s] a sixpence (2½p).

(b) [early–mid-19C] a shilling (5p).

2. as parts of the body [their physical functions as joints].

(a) [mid-19C–1940s] the arm .

(b) [mid-19C–1940s] the elbow; often in phr. over the bender

(c) [mid-19C+] the leg [lapsed in mainstream sl. by 1900 but adopted by US blacks c.1940].

(d) [mid-19C; 1940s–50s] the knee.

3. as a homosexual, and related uses [note Guild Dict. (1965): ‘bender: A homosexual who submits to passive anal intercourse’].

(a) [1940s+] a male homosexual; also attrib.

(b) [1990s+] a term of abuse for an unpopular individual, esp. juv.

(c) [2000s] (N.Z.) a Catholic [? link to sense 2, i.e. f. a Protestant perspective].

In phrases

over the bender [‘it is historical in common English that a declaration made over the elbow as distinct from not over it need not be held sacred. Probably from early Christian if not pagan times. The bender is always the left elbow...’ (Ware). Note also the Victorian custom of ‘over the left’, i.e. pointing with one’s right thumb over one’s left shoulder, implying disbelief]

[mid-19C–1900s] a phr. implying that the previous statement is untrue (cf. bender! excl.).