腦殘粉 [脑残－]

Jyutping nou5 caan4 fan2
Pinyin nǎo cán fěn

Definitions (CC-CEDICT)
  1. (slang) fanboy
  2. fangirl
Definitions (Wiktionary)
  1. noun, derogatory, neologism, slang
    brain-damaged fan; crazily obsessed fan