#foam  a lightweight material in cellular form; made by introducing gas bubbles during manufacture
  supertype:  material.substance__stuff  the tangible substance that goes into the makeup of a physical object; "coal is a hard black material"; "wheat is the stuff they use to make bread"
  subtype:  Styrofoam  (trademark) a light resilient foam of polystyrene
  subtype:  foam_rubber  spongy rubber; made by introducing air bubbles before vulcanization

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