The term "dark matter" is used to describe a hypothetical form of matter that does not interact with or emit electromagnetic radiation, such as visible light. The name "dark matter" is derived from the fact that it cannot be directly observed or detected using traditional methods of observation, hence appearing "dark" or invisible.
The term "matter" is used because dark matter is postulated to possess mass and gravitational effects, similar to ordinary matter. Dark matter's existence is inferred from its gravitational influence on visible matter, such as galaxies and galaxy clusters. It is believed to play a significant role in the structure and evolution of the universe.
While the name "dark matter" may be somewhat misleading, it is important to note that it was coined based on the observed effects of this mysterious form of matter. Scientists continue to study and investigate dark matter using a variety of experimental and theoretical approaches, but its precise nature and composition remain unknown.