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pho·ton·ics

(fō-tŏnĭks)

n. (used with a sing. verb)

The study or application of electromagnetic energy whose basic unit is the photon, using technology such as optics, lasers and other light sources, fiber optics, electrical engineering, and materials science in numerous applications including communications, electrical engineering, materials science, and information storage and processing.

Indo-European & Semitic Roots Appendices

Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:

Indo-European Roots

Semitic Roots

The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.

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