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| et·a·lon [ áyt'l òn, étt'l òn ] (plural et·a·lons) |
noun |
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| Definition: |
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optical instrument that measures wavelengths: a spectroscopic device that has two flat parallel reflecting surfaces. Use: measuring wavelengths.
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| [Early 20th century. < French étalon "standard" < Old French estal "standing place"] |
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