home-made
apricot, raspberry, strawberry, etc.

dollop (BrE)
jar, pot (BrE)

make
spread (sth with)
She spread the toast thinly with raspberry jam.

jar (BrE)
doughnut (BrE), sandwich (esp. BrE), tart (BrE)

bread and jam

constantly
People constantly jammed the street.

up
The traffic will just jam up our village.

be jammed full (of sth)
The cupboards were jammed full of old newspapers.

be jammed solid (esp. BrE)
The traffic was jammed solid on the bridge.

be jammed tight with sth
The room is jammed tight with furniture.

be jammed together
We were jammed together shoulder to shoulder.

be jammed with
The airport was jammed with people trying to arrange flights.

Jam is used with these nouns as the subject:
gun

Jam is used with these nouns as the object:
finger, mechanism, signal, switchboard