casus belli (n.)youdaoicibaDictYouDict
1849, from Latin casus "case" (see case (n.1)) + belli, genitive of bellum "war" (see bellicose). An act justifying war.
Caucasus (n.)youdaoicibaDictYouDict
mountain range between Europe and the Middle East, from Latin Caucasus, from Greek kaukasis, said by Pliny ("Natural History," book six, chap. XVII) to be from a Scythian word similar to kroy-khasis, literally "(the mountain) ice-shining, white with snow." But possibly from a Pelasgian root *kau- meaning "mountain."