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vitamin K₁

1. A yellow viscous oil, C₃₁H₄₆O₂, found in leafy green vegetables and used by the body in the synthesis of prothrombin. Also called phylloquinone.

2. A synthetic analog of this vitamin, used in the treatment of some coagulation disorders and to prevent hemorrhagic disease in newborns. In veterinary medicine, it is used as an antidote to poisoning by anticoagulant rodenticides. Also called phytonadione.

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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