Real Dictionary

motion
countable noun: A motion is a formal proposal or statement in a meeting, debate, or trial, which is discussed and then voted on or decided on.
countable noun: A motion is an action, gesture, or movement.
countable noun: Some people, especially doctors or nurses, use motion as a polite way of referring to a person's act of defecation or the faeces produced.
uncountable noun: Motion is the activity or process of continually changing position or moving from one place to another.
verb: If you motion to someone, you move your hand or head as a way of telling them to do something or telling them where to go.

motion in American English
the act or process of moving; passage of a body from one place to another; movement
noun: the action or process of moving or of changing place or position; movement

motion in British English
noun: Sir Andrew. born 1952, British poet and biographer; his collections include Pleasure Steamers (1978) and Public Property (2002): poet laureate (1999–2009)
noun: the process of continual change in the physical position of an object; movement