Answer:
Bodies of ice and rock that orbit the Sun and produce a coma and tail of vapor and dust when near the Sun
Step-by-step explanation:
Comets are defined by NASA as:
"...frozen leftovers from the formation of the solar system composed of dust, rock, and ices. They range from a few miles to tens of miles wide, but as they orbit closer to the Sun, they heat up and spew gases and dust into a glowing head that can be larger than a planet."
Hope this helped! :^)