1. To bend lower or toward the ground. Someone pushed me while I was leaning down to pick up a piece of paper. I had to lean down to get through the tiny door.

2. To bend someone or something lower or toward the ground. In this usage, a noun or pronoun is used between "lean" and "down." Would you mind leaning that lamp down so I can see what I'm working on? I had leaned the toddler down so he could reach the toy he had dropped on the ground.