Borrowed from Korean 고춧가루 (gochutgaru).
gochugaru (uncountable)
- A red pepper powder used in Korean cuisine.
2016 July 1, David Tanis, “Spicy Cold Noodles Offer an Antidote to Summer Heat”, in New York Times[1]:But the bright red Korean red pepper flakes, gochugaru, are without seeds and are only medium hot, so you can use a lot of them.