Someone cool or an item of clothing that is a mix between a lab coat and a hoodie.
This one time, a chemie lent me a (expensive item), alas, begging did not work for the second time.
I wore a chemie out to brunch and some nubs came up and asked if I could run some numbers in my head for them.
Used in the RuneScape community as an extremely harsh word used to define someone of horrendous odour. Chemies also tend to be immense noobs, with nothing better to do than linger around projecting their smell.
Look at that chemie - what a stinky, vile little noob.