1. To acquire or provide for one's needs by benefiting from or taking advantage of someone or something else. You can't just keep living off your brother—you need to get out there and find a job and a place of your own. I've been living off of my trust fund until I find a new job.

2. To survive by eating or drinking something, especially exclusively or very frequently. A species of insect lives off this weed, so if it is eliminated completely, the insects will die, too. I was so poor during college that I lived off of rice, beans, and pasta.