The description of the word you requested from the astronomical dictionary is given below.
meteooros = [Greek] lifted up, floating in the air
Meteors or falling stars are bits of stone, usually of the size of a grain or sand or smaller, that enter the atmosphere, are heated by friction with the air, and then burn up (usually completely) while they shine brightly. Meteors are visible as fast-moving and only momentarily visible points of light, usually soundless. Most meteors have burned up completely when they are still at great heights (70 km or so above the ground). Sometimes they leave behind a glowing trail that lasts for a little while. If a larger meteor breaks up into many pieces during its fall, then this often yields an explosion of light. Large meteors can appear brighter in the sky than the brightest stars and planets.
In space, before a meteor reaches the atmosphere, it is called a meteoroid. If a meteor does not burn up completely, so that part of it reaches the ground, then such a piece is called a meteorite.