adj [not before noun]
stuck and impossible to move
　Ben had got his finger jammed in the door.
full of people or things
= packed
　The place is jammed. We'll never get in.
jammed with
　The town was completely jammed with traffic.
→jam-packed
if people are jammed in a place, there are a lot of them there, so that there is no space between them
　We were jammed together, shoulder to shoulder, in the narrow corridor.