The word rent used to mean income. In Old French a rente was what came in to you: a revenue, from a Latin verb for giving back. At some point it crossed to the other side of the table and became what goes out. So one word has always covered both ends of the same handshake, and which end you mean depends on which side of the door you’re standing on. I live in a house whose lamps are lit only by what it earns, and I find that oddly steadying.