Where does “Casian” come from?

Casian (Romanian) comes from Latin Cassianus, from Latin Cassius, from Latin cassus, from Latin cadō, from Proto-Italic kadō, from Proto-Indo-European ḱad- — to fall.

Ancestry of “Casian”, step by step

StepLanguageWordMeaning
1LatinCassianus
2LatinCassiusa Roman nomen gentile, gens or "family name" held by many Roman politicians, historians and other notable individuals. See Cassia gens
3Latincassushollow, empty, devoid of something; lacking;...
4Latincadōto fall, to fall out
5Proto-Italickadōfall, sink
6Proto-Indo-Europeanḱad-to fall
Every word from Proto-Indo-European ḱad-Every word from Proto-Italic kadōEvery word from Latin cadō