1. To enter something or some place in a disorderly mass or group: All six of us piled in the car. The subway doors opened and the passengers piled in.
2. To move some people into something or some place in a disorderly fashion: Pile the kids in the van and let's go. I opened the cellar door and piled the logs in. The truck is full and I don't think we can pile in any more rugs.