Where does “ꦏꦸꦏꦸꦃ” come from?

ꦏꦸꦏꦸꦃ (Javanese) comes from Old Javanese kukuh, from Proto-Malayo-Polynesian *kukuq — stick to, adhere firmly.

ꦏꦸꦏꦸꦃ (Javanese): solid, strong, unmovable