The terms "asteroid", "meteoroid", "meteor", and "meteorite" are defined by their location and state.
Asteroids are rocky bodies that orbit the Sun. They are typically larger than meteoroids, but smaller than planets.
Meteoroids are smaller rocky bodies that orbit the Sun. They are typically too small to be seen with the naked eye.
Meteors are meteoroids that enter Earth's atmosphere. They are typically vaporized by the heat of the atmosphere, but sometimes they survive and hit the ground.
Meteorites are meteors that have survived their passage through Earth's atmosphere and hit the ground.
So, if a smaller celestial body collides with a larger celestial body, but neither is classified as a planet, then the smaller celestial body would be called a meteoroid. The collision would be called a meteoroid collision.
There is no logic in saying "meteor" even when there is virtually no atmosphere involved. The term "meteor" is specifically used to describe a meteoroid that is entering or traveling through Earth's atmosphere. If there is no atmosphere involved, then the object cannot be a meteor.
In the case of a collision between two celestial bodies in space, the terms "asteroid collision" or "celestial body collision" would be more appropriate.