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{%type%} Definitions

WordNet 3.0Copyright Princeton University
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n. - The physical property of a medium as determined by its index of change in direction of a propagating wave (light or sound) when passing from one medium to another

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Usage examples (1)
  • A want of clearness, resulting from the haziness and refractiveness of the terrestrial atmosphere, not to mention those fatal defects in the reflector that the art of...
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