Dirt n.
  1. Any foul of filthy substance, as excrement, mud, dust, etc.; whatever, adhering to anything, renders it foul or unclean; earth; as, a wagonload of dirt.
     Whose waters cast up mire and dirt.   --Is. lvii. 20.
  2. Meanness; sordidness.
     Honors . . . thrown away upon dirt and infamy.   --Melmoth.
  3. In placer mining, earth, gravel, etc., before washing.
  Dirt bed Geom., a layer of clayey earth forming a stratum in a geological formation. Dirt beds are common among the coal measures.
  Dirt eating. (a) The use of certain kinds of clay for food, existing among some tribes of Indians; geophagism. --Humboldt. (b) Med. Same as Chthonophagia.
  Dirt pie, clay or mud molded by children in imitation of pastry. --Otway (1684).
  To eat dirt, to submit in a meanly humble manner to insults; to eat humble pie.