ravis.

From a root shared with the Classical Latin adjective raucus and an adjective ravus (“hoarse”) (attested in Paulus Diaconus's epitome of Festus); uncertain further origin. Probably distinct in origin from the adjective rāvus (“gray”). For the ending -is, the TLL compares the deverbal nouns scobis, trudis and torris. Proposed derivations of the root include: * From Proto-Indo-European *h₃rewH- (“to shout, to roar”). Cognates include Latin rūmor (“noise”), Latvian rukt (“to shout”), Proto-Slavic *řuti (“to roar”), Sanskrit रव (rava, “roaring, howling”), Avestan 𐬎𐬭𐬎𐬎𐬀𐬙𐬋 (uruuatō, “roaring”), Ancient Greek ὠρύομαι (ōrúomai, “to howl, roar”). This derivation is preferred by De Vaan, due to connecting more cleanly to cognates outside of Italic, as well as yielding a more satisfying explanation for the -a- vowel. * From earlier Proto-Indo-European *Hr̥h₁-wó-, from a root *Hreh₁- (“to shout, sound”); compare Sanskrit राय॑ति (rā́yati, “to bark”) (< Proto-Iranian *HraH-ya-) and Old Norse rámr (“hoarse”) (< Proto-Germanic *rēmaz), though these also have alternative explanations. * Onomatopoeic.