This phrasal verb has many, many meanings.
1. flee - They wanted to run off before the trouble started.
2. print or make photocopies - He ran off two-hundred advertisements.
3. write something in a hurry - She could run off an essay at a moment's notice.
4. spill - Rainwater ran off the roof.
5. leave without notice - Her husband ran off to France.
6. operate from a source of power - The computer runs off batteries.
7. chase someone or something away - If anyone comes, run them off.
8. run off at the mouth - talk without ceasing
9. run off with someone - leave in the company of someone with the intention of marriage or cohabitation.