a cellist who is a fan of Apocalyptica, the rock group which does classical/Metallica-type stuff, but arranged for cello.
person 1: doing anything over the weekend?
person 2: yeah, me and a couple of other cellisticas at Juilliard got tickets to the Apocalyptica thing on next saturday.
person 1:sweet.
A hardo is a person who tries extremely hard at everything. Most times a hardo will try very hard at things that do not require excessive effort. For example, sports practices, gym class, etc.
Wow did you see Jack at practice today? What a hardo!