"Čuk" is an oeconym rather than a surname, referring to the farm at Stara Vrhnika no. 19. The associated surname in the mid-19th century was Grum (Grom). Source: Kos, Janez. 2010. "Prebivalci Stare Vrhnike po popisu duš od leta 1834 do 1847." Vrhniški razgledi 11: 65-83.