Someone who is obsessed with fancy writing implements and typically uses a different strange pen every day or even every hour.
You can often tell a pen slut by looking at his/her desk: if there are
more than 20 Pilot Hi-Precisions, PhD retractables, Marvy
Sparklers, and/or fancy souvenir pens, that's a sign. Also, if you ask a pen slut to borrow a pen, he/she will likely rummage around for a Bic ballpoint rather than allow you to use a
masterpiece such as his/her Y&C Gell Extreme 0.7 with teal ink.
I am a pen slut; on my desk at work, I have three five-compartment pencil cups that hold a total of 84 pens. My favorites are the Marvy Gel Excels and the San Fran
one with the moving
cable car in the barrel. No you CANNOT borrow them.