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tre·foil

(trēfoil′, trĕfoil′)

1. Any of various plants of the pea family, chiefly of the genera Trifolium and Lotus, having compound trifoliolate leaves.

2. An ornament, symbol, or architectural form having the appearance of a trifoliolate leaf.

[Middle English, from Anglo-Norman trifoil, from Latin trifolium : tri-, tri- + folium, leaf; see bhel-³ in the Appendix of Indo-European roots.]

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trefoil

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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