Crank (kr?nk), n. [OE. cranke; akin to E. cringe, cringle, crinkle, and to crank, a., the root meaning, probably, “to turn, twist.” See Cringe.] 1. (Mach.) A bent portion of an axle, or shaft, or an arm keyed at right angles to the end of a shaft, by which motion is imparted to or received from it; also used to change circular into reciprocating motion, or reciprocating into circular motion. See Bell crank.
2. Any bend, turn, or winding, as of a passage.
So many turning cranks these have, so many crooks.
Spenser.
3. A twist or turn in speech; a conceit consisting in a change of the form or meaning of a word.
Quips, and cranks, and wanton wiles.
Milton.
4. A twist or turn of the mind; caprice; whim; crotchet; also, a fit of temper or passion.
Violent of temper; subject to sudden cranks.
Carlyle.
5. A person full of crotchets; one given to fantastic or impracticable projects; one whose judgment is perverted in respect to a particular matter.
6. A sick person; an invalid.
Thou art a counterfeit crank, a cheater.
Burton.
Crank axle(Mach.), a driving axle formed with a crank or cranks, as in some kinds of locomotives. — Crank pin(Mach.), the cylindrical piece which forms the handle, or to which the connecting rod is attached, at the end of a crank, or between the arms of a double crank. — Crank shaft, a shaft bent into a crank, or having a crank fastened to it, by which it drives or is driven. — Crank wheel, a wheel acting as a crank, or having a wrist to which a connecting rod is attached.