Scrub

Scrub is a very broad term that can be used as an insult or a compliment or just a word. It is the root of Scrubjumper.

Examples
A: Hey do you know Cubit? B: Yeah, he's a scrub.

A: Hey scrub!

A: What a scrub!

A: Stop scrubbin around(verb)

A: Scrub me sideways(cat)