faun n.

"broad, shallow vessel of metal used for domestic purposes," Middle English panne, from Old English panne, earlier ponne (Mercian) "pan," from Proto-Germanic *panno "pan" (source also of Old Norse panna, Old Frisian panne, Middle Dutch panne, Dutch pan, Old Low German panna, Old High German phanna, German pfanne), probably an early borrowing (4c. or 5c.) from Vulgar Latin *patna. This is supposed to be from Latin patina "shallow pan, dish, stew-pan," from Greek patane "plate, dish," from PIE *pet-ano-, from root *pete- "to spread."

But both the Latin and Germanic words might be from a substrate language [Boutkan]. Irish panna probably is from English, and Lithuanian panė is from German.

The word has been used of any hollow thing shaped somewhat like a pan; the sense of "head, top of the head" is by c. 1300. It was used of pan-shaped parts of mechanical apparatus from c. 1590; hence flash in the pan (see flash (n.1)), a figurative use from early firearms, where a pan held the priming (and the gunpowder might "flash," but no shot ensue). To go out of the (frying) pan into the fire "escape one evil only to fall into a worse" is in Spenser (1596).

1771, "the total of the animal life of a certain region or time, from Late Latin Fauna, a rustic Roman fertility goddess who was wife, sister, or daughter (or some combination) of Faunus (see faun).

Popularized by Linnaeus, who adopted it as a companion word to flora and used it in the title of his 1746 catalogue of the animals of Sweden, "Fauna Suecica." First used in English by Gilbert White (1720-1793) the parson-naturalist.

personification of the west wind in Roman mythology, from Latin Favonius, which de Vaan suggests is cognate with the god-name Faunus (see faun), from a prehistoric noun meaning "who favors" (see favor (n.)):

This also yields a good semantic motivation: the wind that stimulates vegetation can be called favourable. Favonius was regarded by the Romans as the herald of spring and the start of new vegetation (e.g. Cato Agr. 50.1, Cicero Ver. 5.27, Lucretius 1.11, Vitruvius 2.9.1).

The Latin word is the source (via Old High German phonno, 10c., via Vulgar Latin contraction *faonius) of German Föhn "warm, dry wind blowing down Alpine valleys." Related: Favonian.