O.E. sceanca "leg, shank, shinbone," from P.Gmc. *skankon- (cf. M.L.G. schenke, Ger. schenkel "shank, leg"), perhaps lit. "that which bends," from PIE base *skeng- "crooked" (cf. O.N. skakkr "wry, distorted," Gk. skazein "to limp"). Specifically, the part of the leg from the knee to the ankle. Shank's mare "one's own legs as a means of transportation" is attested from 1774. The verb, originally in golf, meaning "to strike (the ball) with the heel of the club" is recorded from 1927.
A stiletto-like weapon: We'd yoke him with a shank/ looks like a large screwdriver and is known in prison parlance as a shank(1950s+ Prison & street gang)
The end or last part of a period of time, esp of the evening • Also interpreted as the early or chief part of a period of time: Let's have one for the road, my friends; it's the shank of the evening(1828+)
To stab: that dude the dicks want for shanking his old lady
To kick: is shanking punts all over the lot(1970s+ Football)
[all senses reflect the basic notion of something long and thin, like a leg bone]
The Dictionary of American Slang, Fourth Edition by Barbara Ann Kipfer, PhD. and Robert L. Chapman, Ph.D. Copyright (C) 2007 by HarperCollins Publishers. Cite This Source