#softener  a substance added to another to make it less hard
  supertype:  chemical  produced by or used in a reaction involving changes in atoms or molecules
  subtype:  conditioner.softener  a substance used in washing (clothing or hair) to make things softer
  subtype:  plasticizer  a substance added to plastics or other materials to make them more pliable
  subtype:  water_softener__watersoftener  a substance that lessens the hardness of water giving it more efficient sudsing

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