Where does “carus” come from?

carus (Latvian) comes from Latvian cars, from Russian царь, from Old East Slavic цьсарь, from Old East Slavic цѣсарь, from Proto-Slavic cěsařь, from Proto-Germanic kaisaraz, from Latin Caesar, from Latin caesaries — hair.

carus (Latvian): accusative plural form of cars