Biblically, "crooked" meant "twisted", "corrupt", or "not straight".

William Crookes, English chemist

George Crook, an American general

Mackenzie Crook, a British actor

Crooked Music (Schräge Musik) was a very effective firing system developed by the Germans in World War II which allowed their fighter aircraft to shoot down Allied bombers.

Crook County, Oregon, United States

Crook, Colorado, United States

George Crook summary and related information.

Crook, County Durham, England

Ann Marie Crooks, a female bodybuilder and professional wrestler

Crooking is a verb to refer to the action of creating a bend or curve; for example, crooking a finger. Hence a crook may be anything that is crooked.

Specifically, a crook is a tool with a crook in it, such as a shepherd's staff or prelate's crosier; see also flail and crook.

In music, a crook is a length of tubing used to change the pitch of a natural horn or other brass instrument; by removing one crook of a given length and replacing it with a crook of another, the entire pitch of the instrument would change. A crook is also the term for a bent or curved pipe that connects the reed to the instrument body on some double reed instruments; in American usage this is generally called a bocal. Musicians who play the natural horn (the predecessor to the modern horn) use crooks to change the instrument into different keys. These are pieces of tubing that are inserted into the horn to change its length.

Crook, a slang term for a criminal or a person of questionable morality. Specifically it refers to someone who is corrupt and uses dishonest or unethical tactics to gain money. The adjective crooked can refer to such persons or actions. This version of the term may also be archaically used as a verb in reference to becoming a criminal or causing another to become a criminal.

In Australian slang, crook (adjective) means unwell (amongst other meanings).

Shepherd's staff