What is the definition of meteor?

A meteor is the visible trail of light made by a meteoroid that enters the Earth's atmosphere, and then either burns up, explodes (bolides), or hits the surface on land or at sea.

Meteors can have several different compositions, containing various stony, glassy, or metallic materials. (sometimes called a shooting or falling star).

A meteoroid is a sand to boulder sized particle of debris in the Solar System They can vary in size from as small as a grain of sand to as big as boulders.

A meteorite is any part of a meteor that makes it to the Earths surface.
A meteor is a small body of matter from outer space that enters the earth's atmosphere, becoming incandescent as a result of friction and appearing as a streak of light. Some synonyms could be:

falling star, shooting star, meteorite, meteoroid, and bolide. A sentence you could use is, 'The meteor shot through the sky.' It is also a noun.