덕질

Deeply immersing yourself in fandom activities — buying merch, collecting photocards, watching fancams, attending concerts, streaming albums. Not just being a fan, but fully committing to it. From 덕후 (otaku/hardcore fan) + 질 (activity/behavior).

덕 = hardcore fan (shortened from 오'덕'후, Korean pronunciation of Japanese 오타쿠)

질 = activity / behavior