Dark matter is a hypothetical form of matter that does not emit or reflect enough electromagnetic radiation to be observed directly, but whose presence can be inferred from gravitational effects on visible matter. According to present observations of structures larger than galaxies, as well as Big Bang cosmology, dark matter accounts for the vast majority of mass in the observable universe.
On the other hand...
Dart Matter is an unseen mass with a power so great it can only be used for good or evil.
Dart Matter Chatter