meteoroid

noun

A solid body, moving in space, that is smaller than an asteroid and at least as large as a speck of dust.

noun

A body traveling in space, and of the same nature as those which on entering the earth’s atmosphere become visible as meteors.

noun

A small body moving through space, or revolving about the sun, which on entering the earth’s atmosphere would be deflagrated and appear as a meteor.

noun

A relatively small (sand– to boulder-sized) fragment of debris in a solar system that produces a meteor when it hits the atmosphere

noun

(astronomy) any of the small solid extraterrestrial bodies that hits the earth’s atmosphere