quartus

From Proto-Indo-European *kʷeturtos ~ *kʷetwr̥tos (whence Ancient Greek τέταρτος (tétartos), Sanskrit चतुर्थ (caturtha), Proto-Balto-Slavic *ketwirtas and Proto-Germanic *fedurþô), from *kʷetwóres (“four”). Cognate to quadrus (“square”), from sense “four-sided”. For the phonetic development, De Vaan cites Schrijder positing *kʷtwr̥to- > (with voicing of t) *kʷdwr̥to- > *kʷadworto-, followed by dw > w (cf. suāvis). The resulting *kʷawortos would regularly become quārtus (cf. Māvors > Mārs).

• (Classical Latin) IPA^(key): /ˈkʷaːr.tus/, [ˈkʷäːrt̪ʊs̠]
• (modern Italianate Ecclesiastical) IPA^(key): /ˈkwar.tus/, [ˈkwärt̪us]

quārtus (feminine quārta, neuter quārtum); first/second-declension numeral

1. fourth, the ordinal number after tertius and before quintus

First/second-declension adjective.

• quārtārius

• “quartus”, in Charlton T. Lewis and Charles Short (1879) A Latin Dictionary, Oxford: Clarendon Press
• “quartus”, in Charlton T. Lewis (1891) An Elementary Latin Dictionary, New York: Harper & Brothers
• quartus 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)
• quartus in Gaffiot, Félix (1934) Dictionnaire illustré latin-français, Hachette.
• De Vaan, Michiel (2008) “quattuor”, in Etymological Dictionary of Latin and the other Italic Languages (Leiden Indo-European Etymological Dictionary Series; 7), Leiden, Boston: Brill, →ISBN, page 505