[FrustratedMonky]

Wasn't the term 'dark matter' just meant to indicate 'unknown'.

It wasn't meant to be descriptive, just that there is a gap between theories.

And one theory is there is some 'unknown' type of matter, and they called it dark.

[bhickey]

No. 'Dark' comes from 'dunkle' in German. It refers to non-luminous matter.