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cit·rul·line

(sĭtrə-lēn′)

An amino acid, C₆H₁₃N₃O₃, originally isolated from watermelon, that is produced as an intermediate in the conversion of ornithine to arginine during urea formation in the liver.

[New Latin Citrullus, watermelon genus (from Medieval Latin citrullus, watermelon, from Italian dialectal citrulo, from Late Latin citrium, from Latin citrus, citron) + -INE².]

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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