What is the meaning of Crankshaft?

A rotating shaft with throws (parts that stick out) and which drives, is driven by (cranked by), or functions as a crank.

To deform in such a manner that part of the rod or bolt is displaced sideways, offset from the longitudinal axis of the part, but remains parallel with the part's main longitudinal axis, with the final shape somewhat resembling a crankshaft.

Source: wiktionary.org