The Brief: "MV" is an abbreviation for "music video."

DEEP DIVE
MV is a common abbreviation used online by K-pop stans. It stands for “music video.”
#SuperJunior’s “No Other” Becomes Their 4th MV To Hit 100 Million Views https://t.co/UjceaUjLy8 pic.twitter.com/auE489NYz1
— Soompi (@soompi) August 6, 2020