Javert is also a verb, derived from the same meaning. To javert someone is to never stop chasing them up for something.
"Oh geezer, my german teacher is really javerting me for my homework, maybe i should Jean Valjean it"
As a noun, Javert refers to a person of similar characteristics: ruthless, obsessive, perfectionist. It may also refer to a television trope (or cliche), describing a character that fills a similar role of the actual Javert from Hugo's novel.
Javert may also be used as a verb, referring to the act of relentlessly chasing someone or something.