means A long, slender rod or column — whether the spinning rod that transmits power in a machine, the handle of a tool, a beam of light, or a vertical passage sunk into the earth.

from From Old English 'sceaft,' meaning the shaft of a spear or an arrow — a straight wooden pole. It has solid Germanic relatives, like Old Norse 'skapt' and German 'Schaft,' and is probably tied to a root meaning 'to scrape' or 'shave,' since a shaft was a length of wood pared down smooth and straight. From that spear-pole the word reached outward to anything long and thin: the shaft of a column, a shaft of sunlight, a mine shaft, and eventually the spinning rods inside our machines. The modern slang 'to get shafted' leans on that same old image of being run through with a pole.