See ice fog.
[From Western Shoshone pakenappeh : pakena-, fog (akin to Cahuilla páxiš, fog, both Shoshone and Cahuilla from earlier *pa-ki-, perhaps ultimately from Proto-Uto-Aztecan *pā-, water) + -ppeh, suffix for stative nouns or nouns considered to be in an inalterable state.]
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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.