Real Dictionary

crank
countable noun: If you call someone a crank, you think their ideas or behaviour are strange.

crank in American English 1
a handle or arm bent at right angles and connected to a shaft of a machine, used to transmit motion or to change rotary motion into reciprocating motion, or vice versa
to form into the shape of a crank
to turn a crank, as in starting an engine or operating a device
intransitive verb: to turn a crank, as in starting an automobile engine
noun: 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
transitive verb: to bend into or make in the shape of a crank

crank in American English 2
cranky (sense 5)
adjective: having a tendency to roll easily, as a boat or ship; tender (opposed to stiff)
noun: a crank vessel

crank in American English 3
high-spirited; lively
adjective: lively; high-spirited

crank in Automotive Engineering
noun: A crank is an arm attached to a shaft that carries a handle or pedal parallel to the shaft.

crank in British English 1
noun: a device for communicating motion or for converting reciprocating motion into rotary motion or vice versa. It consists of an arm projecting from a shaft, often with a second member attached to it parallel to the shaft

crank in British English 2
adjective: (of a sailing vessel) easily keeled over by the wind; tender

crank in Mechanical Engineering
noun: A crank is a device for transferring motion from one part to another or for changing one type of motion to another. It consists of an arm sticking out from a shaft.