When a beginner osu! player says they can play high star maps after a few days of experience, but they had NoFail(NF) on all along, shocking experienced players and temporarily make them regret ever trying.

n. The birth name of somebody who has changed their name. Most commonly attributed to trans people, but can be attributed to any person who has changed their name. (sometimes written as two words: dead name)

v. 1. To call somebody by their deadname.
v. 2. To out somebody's deadname to the public.