1. A double-ringed, crystalline organic base, C5H4N4, that is the parent compound of a large group of biologically important compounds.
2. Any of a group of substituted derivatives of purine, including the nitrogen bases adenine and guanine, which are components of nucleic acids. Uric acid, caffeine, theobromine, and theophylline are also purines.
[German Purin : blend of Latin pūrus, clean; see PURE, and New Latin ūricus, uric (from Greek ouron, urine) + -in, -in, -ine.]
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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:
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.