"The nickname is 도람프 or 도람푸 — a play on the Korean word that means to be crazy/insane/mad.
Krista Ryu remarks:
돌다 (dolda) literally means to turn (v)
But when you use it after the word 'head' or directly to a person, it can mean you are crazy or 'nuts'.
So it is a combination of this verb and the name Trump
Trump in Korean transliterated would be Teuleompeu 트럼프
(Some one is crazy) dol-assda 돌았다 ('turned')
–> dolampeu 도람프"Approve.