velox

From Proto-Indo-European *h₂weh₁-lo- (“wind”), from *h₂weh₁- (“to blow”), named after the speed of wind.^[1]

Older theories derive the word from Proto-Italic *weksloks, from Proto-Indo-European *weǵʰ- (“to bring, transport”) (whence vehō).

• (Classical Latin) IPA^(key): [ˈweː.ɫoːks]
• (modern Italianate Ecclesiastical) IPA^(key): [ˈvɛː.loks]

vēlōx (genitive vēlōcis, comparative vēlōcior, superlative vēlocissimus, adverb vēlōciter); third-declension one-termination adjective

1. swift, quick, fleet, rapid, speedy

   Synonyms: rapidus, celer, properus, levis, prōmptus, facilis

   Antonyms: lentus, tardus, sērus

   Pestilentī dēsertā regiōne vēlōciōrī sē fugā prōripiunt.

   (please add an English translation of this usage example)

According to Döderlein, celer and citus mean "swift, fast, quick" in terms of quick motion (in general) with tardus as their antonym. More specifically, citus refers to a lively motion, whereas celer refers to an eager or impetuous motion.

On the other hand, vēlōx and pernīx as "quick" denote a level of athletic nimbleness in terms of bodily activity, with lentus as their antonym. More specifically, pernīx involves a level of dexterity and quickness in an eclectic range of actions (such as climbing, hurdling, jumping, vaulting, etc.); whereas vēlōx is especially used for running, swimming and flying (moving in a direction)

Thirdly, properus and festīnus as "quick" refer specifically to one's speed in terms of the shortest time to reach a destination, with sēgnis as their antonym. More specifically, festīnus intimates a certain level of impatience, whereas properus simply indicates a haste from energy simply.

Third-declension one-termination adjective.

• Pokorny, Julius (1959) Indogermanisches etymologisches Wörterbuch [Indo-European Etymological Dictionary] (in German), volume 3, Bern, München: Francke Verlag, page 1118
• “velox”, in Charlton T. Lewis and Charles Short (1879) A Latin Dictionary, Oxford: Clarendon Press
• “velox”, in Charlton T. Lewis (1891) An Elementary Latin Dictionary, New York: Harper & Brothers
• velox in Gaffiot, Félix (1934) Dictionnaire illustré latin-français, Hachette.