Earthenware is referred to as a clay body which is fired to relatively low temperatures (below 1150C) and which, after firing remains porous in its unglazed state.

See also:
"Earthenware" is in the NAICS Code "327111"
  (Vitreous China Plumbing Fixture and China and Earthenware Bathroom Accessories ManufacturingTowel bar holders, vitreous china and earthenware, manufacturing)