arcus

Borrowed from Latin arcus. Doublet of arc and arco. Distantly related to arrow.

arcus (plural arcus)

1. (medicine) A white band of cholesterol that forms at the edge of the cornea
2. (meteorology) A low, horizontal cloud typically forming at the leading edge of thunderstorm outflow
3. (entomology) An elastic band around the base of the arolium, a pad at the end of the leg of certain insects
4. (palynology) An arc-shaped band of thickened sexine extending between two apertures on a pollen grain or spore

• arc
• arcuate
• arcus juvenilis
• arcus senilis

• Curas, carus, scaur

From Proto-Indo-European *h₂erkʷos (“bow, arrow”). Cognate to Old English earh, whence English arrow.

• (Classical) IPA^(key): /ˈar.kus/, [ˈärkʊs̠]
• (modern Italianate Ecclesiastical) IPA^(key): /ˈar.kus/, [ˈärkus]

arcus m (genitive arcūs); fourth declension

1. arc, arch
2. bow (arc-shaped weapon used for archery)
3. rainbow

Fourth-declension noun (dative/ablative plural in -ubus).

• arcuātus

• discus
• sagitta

• “arcus”, in Charlton T. Lewis and Charles Short (1879) A Latin Dictionary, Oxford: Clarendon Press
• “arcus”, in Charlton T. Lewis (1891) An Elementary Latin Dictionary, New York: Harper & Brothers
• arcus in Charles du Fresne du Cange’s Glossarium Mediæ et Infimæ Latinitatis (augmented edition with additions by D. P. Carpenterius, Adelungius and others, edited by Léopold Favre, 1883–1887)
• arcus in Gaffiot, Félix (1934) Dictionnaire illustré latin-français, Hachette
• “arcus”, in Harry Thurston Peck, editor (1898) Harper's Dictionary of Classical Antiquities, New York: Harper & Brothers
• arcus in Ramminger, Johann (accessed 16 July 2016) Neulateinische Wortliste: Ein Wörterbuch des Lateinischen von Petrarca bis 1700‎, pre-publication website, 2005-2016
• “arcus”, in William Smith et al., editor (1890) A Dictionary of Greek and Roman Antiquities, London: William Wayte. G. E. Marindin