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rho·dop·sin

(rō-dŏpsĭn)

Any of a class of reddish, light-sensitive pigments found in the retinal rods of the eyes of terrestrial and marine vertebrates, consisting of opsin and retinal. Also called visual purple.

[RHOD(O)- + Greek opsis, sight; see -OPSIS + -IN.]

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:

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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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