A meteoroid was a piece of astronomical debris, smaller than an asteroid. When a meteoroid entered an atmosphere, it was called a meteor, also colloquially known as a shooting star or falling star, and the remains found after it landed were called meteorites. Really small meteorites were classified as micrometeoroids. (VOY: "Year of Hell, Part II")
A.E. Hodgkin theorized that the termites of Loracus Prime were meteorite-borne before developing Hodgkin's Law of Parallel Planetary Development. (ENT: "Strange New World")
Earth Cargo Service freighters used any chance to upgrade their weapons. When asked by Captain Jonathan Archer why this was, Travis Mayweather replied "Think about it. You're a dozen light years from home with twenty kilotons of dilithium ore in your hold, armed with nothing but a pop-gun for shooting oncoming meteors. What would you do?" (ENT: "Fortunate Son")
In 2254, as the USS Enterprise was deflecting meteoroids, the starship detected something heading in the direction of the ship. José Tyler thought it could be the meteoroids; Una Chin-Riley disagreed, saying it was not the meteoroids. Tyler further noted that whatever it was, the ship's meteoroid beam was not deflecting it. (TOS: "The Cage", "The Menagerie, Part I")
The probe Nomad suffered a serious loss of memory after a collision with a meteoroid. (TOS: "The Changeling")
In 2262, the SS Beagle suffered serious damage from a storm of meteoroids. (TOS: "Bread and Circuses")
In 2268, Sulu informed Captain Kirk of a meteor impact on Earth in the region of Siberia whose impact flattened the forest for several kilometers. Kirk dismissed the comment, stating that if he wanted a Russian history lesson, he would have brought Chekov. (TOS: "That Which Survives")
In the revised story outline of the Star Trek: The Original Series episode "Charlie X", the Enterprise traversed "a hail shower of meteoroids." In a memo he wrote John D.F. Black about that outline (the memo was dated 11 May 1966), Robert H. Justman suggested, "This may be duplication of an effect we had in Star Trek I[!] and also in the revised script on 'Mudd's Women[!]'."