a thick sweet substance made from boiled fruit and sugar, eaten especially on bread [↪ jelly]:
food[uncountable and countable]DFF
a jam sandwich
a situation in which it is difficult or impossible to move because there are so many cars or people:
Sorry we're late. We got stuck in a traffic jam.
a situation in which a machine does not work because something is stopping a part from moving:
It caused a jam in the printer.
a difficult situation
difficult situation[countable usually singular] informal
We became friends after he helped me out of a jam.
a jam session
a song or piece of music, especially one by a rap or rock group
6 American English informal
to play rock music loudly and with a lot of energy or emotion:
Make no mistake - these guys know how to kick out the jams.
7 British English informal
good things someone promises you, which never happen:
There is an element of 'jam tomorrow' about some of the government's policies.