[Slang] THAT'S JAM-PACKED. - Grasp Everyday Idioms: Learning About Expressions for Crowdedness
That's jam-packed.
Very crowded.
That’s jam-packed" refers to a place or venue being extremely full or crowded, like how jam is tightly filled in a jar. It conveys a sense of squeezing as much as possible into a space.
Example Sentences
The subway was jam-packed during rush hour.
The subway was extremely crowded during rush hour.
Sorry, can't invite you, the party is jam-packed already.
Sorry, the party is already too crowded to invite more people.
I tried to make a quick stop at the store, but it was jam-packed, so I had to leave.
I tried to make a quick stop at the store, but it was too crowded, so I left.