1. To fit in(side of something) very snugly or compactly. We all had to squash into his tiny truck. I know the bag looks small, but the sleeping bag squashes into it without a problem.

2. To force or compel someone or something to fit inside of something by crushing, compressing, or compacting them or it. In this usage, a noun or pronoun is used between "squash" and "into." I only have one suitcase, so I always have to squash all my clothes into it whenever I travel. They tried to squash 40 of us into that dinky little classroom.