means to perform in the act of sex with another person. It can be used when discussing both giving and receiving sex, or the wish to have sex with someone else. Normally a term used when the use of a phrase such as "getting yer hole" may be deemed too crude or offensive, or if the person using the phrase is in ear shot of someone they would not wish to know that they are having/planning on having sex.
It can also be used when trying to inform someone sex has recently been performed.
Example One (when used in a discussion)
Person 1: "Aye, am goin te his the night. Actually canny wait man, its been too long!"
Person 2: "Oh! Ye think you'll be getting yer ham jam the night then?"
Person 1: (winks) "Oh Aye man."
Person 2: (immediantly grins) "Yaaaas."
Example Two (when used to inform)
Person One: (raises eyebrows) "Here, by ra way, ham jam"
Person Two: (laughs out loud) "Yaaaaas!"