Machinery . any of several types of arms or levers for imparting rotary or oscillatory motion to a rotating shaft, one end of the crank being fixed to the shaft and the other end receiving reciprocating motion from a hand, connecting rod, etc.

Informal . an ill-tempered, grouchy person.

an unbalanced person who is overzealous in the advocacy of a private cause.

an eccentric or whimsical notion.

a strikingly clever turn of speech or play on words.

Archaic . a bend; turn.

Slang . the nasal decongestant propylhexedrine, used illicitly for its euphoric effects.

Automotive Slang . a crankshaft.

to bend into or make in the shape of a crank.

to furnish with a crank.

Machinery . to rotate (a shaft) by means of a crank.

to start (an internal-combustion engine) by turning the crankshaft manually or by means of a small motor.

to start the engine of (a motor vehicle) by turning the crankshaft manually.

to turn a crank, as in starting an automobile engine.

Obsolete . to turn and twist; zigzag.

unstable; shaky; unsteady.

of, pertaining to, or by an unbalanced or overzealous person

a crank phone call; crank mail.

British Dialect . cranky 1 ( def. 5 ) . ?

crank down, to cause to diminish or terminate

the president's efforts to crank down inflation.

crank in or into, to incorporate as an integral part

Overhead is cranked into the retail cost.

crank out, to make or produce in a mass-production, effortless, or mechanical way

She's able to crank out one best-selling novel after another.

crank up, Informal .

to get started or ready

The theater season is cranking up with four benefit performances.

to stimulate, activate, or produce

to crank up enthusiasm for a new product.

to increase one's efforts, output, etc.

Industry began to crank up after the new tax incentives became law.

noun

arm , lever , handle , turning device , eccentric , fanatic , monomaniac , crackpot * , character , zealot , misanthrope , complainer , curmudgeon , grouch , crab , faultfinder , growler , grumbler , grump , murmurer , mutterer , whiner , crazy , lunatic , bend , brace , bracket , crackpot , crook , curve , kook , sourpuss , start , turn , turning-handle , twist , unstable , vigorously , winch , wind