Initially 'low' (eg: a low), Someone at a lower level.
Someone that lacks skills or brain or XP or sense of humour or whatever.
The suffix 'zor' is used as usual to reinforce the meaning.
hohoho you're still lvl 57, you stupid lowZor !?
omg look at that lowzor, he still wears green items !
Why dya break that sheep ffs !?? 'cause I'm low'sir..