1. To push or lean down on someone or something. It's stuck—something is pressing down on the door! They all dogpiled on me, but having all that weight press down on my started giving me an anxiety attack.

2. To push or lean someone or something down on another person or thing. In this usage, a noun or pronoun is used between "press" and "down on." The criminal pressed the hostage down on the ground and put a gun against his head. Press your hand down on the wound to stop the flow of blood. Someone keeps pressing my hat down on me.