(one's) jam noun phrase informal slang
Used to describe one's favourite song.
Whenever I come to my friend’s cafe, I require the waiter to turn on my jam.
My younger brother kept turning up his jam while I was doing homework last night. This made me annoyed.
Something that a person loves or cares about.
I don't want to race the horse as it isn't my jam.
Playing the guitar is his jam, so I think I will give him a guitar on his birthday.
Completely dark, without any light or color
I'm scared of the basement! It's as black as a skillet!