1.
If you run off with someone, you secretly go away with them in order to live with them or marry them.
The last thing I’m going to do is run off with somebody’s husband...
We could run off together, but neither of us wants to live the rest of our lives abroad.
= run away
PHRASAL VERB : V P with n , pl-n V P together
2.
If you run off copies of a piece of writing, you produce them using a machine.
If you want to run off a copy sometime today, you’re welcome to.
PHRASAL VERB : V P n (not pron)