What is the scientific term for the darker colored dust-covered lowland area of the lunar surface?

The scientific term for the darker colored dust-covered lowland areas of the lunar surface is "maria" (singular: "mare"). These basaltic plains were formed by ancient volcanic activity and are less cratered than the surrounding highlands, which gives them a darker appearance. The term "maria" is derived from the Latin Word for "seas," as early astronomers mistakenly believed they were large bodies of water.