"He lives off air."
Translation:Él vive del aire.
I knew a lady who was Dominican (speaks Spanish). She moved back in with her parents and had no plans to look for a job. I asked her what she was going to do for money. She said she would just live off air. I thought she was trying to make a joke about a serious situation. But I wonder if the phrase has a special meaning among Spanish speaking people, such as, maybe, they are going to do whatever they can to get by. Or maybe it means what Philg42 says.