1. Literally, to crush, crumple, or mash something down. A noun or pronoun can be used between "squash" and "down." I kept trying to squash my clothes down to fit them all in the suitcase, but it was hopeless. I wish the courier hadn't squashed down the box to fit it through the mail slot like that!

2. To willfully suppress, inhibit, or quash something. A noun or pronoun can be used between "squash" and "down." If you squash down your anger like that, it's going to end up exploding down the line. The dictator squashed the rebellion down without mercy.