Kos

Czech and Sorbian (Koš): metonymic occupational name for a basketmaker, from koš ‘basket’.

German (Kös): possibly a nickname for a gossip or a smooth-talker, from Middle High German kōse, koese ‘talk’, ‘chat’. Compare Koser.

Jewish (Ashkenazic): of uncertain origin. It may be an ornamental name from Slavic kos ‘blackbird’, as in 1, or alternatively it may be from Hebrew kos ‘drinking glass’ or Yiddish kos ‘goblet’, ‘cup’, probably applied as a metonymic occupational name for someone who made glasses or cups.

Dutch: from a Zeeland personal name derived from Constantius (see Constant).

Hungarian (Kós): from a Turkish loanword kos ‘ram’ (from Old Turkish qoč, Ottoman Turkish qoç); perhaps a metonymic occupational name for a shepherd but more probably a nickname for someone thought to resemble the animal.