per·i·he·li·on (pĕr′ə-hele-ən, -helyən)
n.pl. per·i·he·li·a(-hele-ə, -helyə)
The point in a solar orbit where the orbiting body is closest to the sun.
[Alteration ofNew Latinperihelium : PERI– + Greekhelios, sun; see sāwel- in the Appendix of Indo-European roots.]
(click for a larger image)perihelion
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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.