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