when a borrower of one of your pens (or pencils) neglects to return to you your pen, either mistakenly or on purpose.
Dude, I totally got penjacked by that asshole I lent my pen to in chem the other day!
by Alex Dres October 23, 2007
When sitting in class and someone just steals your pen/pencil when you are not looking.
"Dude you just pen jacked me!"
by Forlex Ravenholdt March 13, 2012