Ὀρόντης

From Akkadian 𒀀𒊏𒀭𒌓 (Arāntu, “Orontes; site of the Battle of Qarqar”) and also in Egyptian jrnt (Arantu/Araunti, “Orontes; river flowing by Qadesh”) attested at least from the period of Ramesses II:

• The meaning of which is contested with connections to: Akkadian 𒀀𒊏𒀭𒌓 (arantu, “a type of grass; fennel”), perhaps in connection to the region around the city of Ugarit, the ruins today being known as رَأْس شَمْرَة (raʔs šamra, “Headland or Cape Fennel”).
• Also connected to Akkadian 𒀀𒊏𒀭𒁺 (araddu, arantu, “wild ass; stubborn”), possibly related to the modern name for the river الْعَاصِي (al-ʕāṣī, “rebel, stubbornly in error, refusing to be corrected”) so-called for its flowing south to the north unlike the rest of the rivers in the region.
• Disputably from Old Median *Arvand; compare Avestan 𐬀𐬎𐬭𐬎𐬎𐬀𐬧𐬝- (a^uruuaṇt̰-, “swift”).

More at Orontes.

Ὀρόντης • (Oróntēs) m (genitive Ὀρόντου); first declension

1. Orontes (river)

• Greek: Ορόντης (Oróntis)
• → Latin: Orontēs

From Old Median *Arēvand, from Proto-Iranian *Raivant-, *Rayivant- (“possessing wealth”); see Old Armenian Երուանդ (Eruand) for more.

Ὀρόντης • (Oróntēs) m (genitive Ὀρόντου); first declension

1. Orontes (name of any one of a number of ancient Armenian kings)

• Woodhouse, S. C. (1910) English–Greek Dictionary: A Vocabulary of the Attic Language‎, London: Routledge & Kegan Paul Limited, page 1,019
• Perixanjan, A. G. (1993) Материалы к этимологическому словарю древнеармянского языка. Часть I [Materials for the Etymological Dictionary of the Old Armenian Language. Part 1]‎ (in Russian), Yerevan: Academy Press, page 7
• Ὀρόντης in Bailly, Anatole (1935) Le Grand Bailly: Dictionnaire grec-français, Paris: Hachette