n. & v.
n. 1 a conserve of fruit and sugar boiled to a thick consistency. 2 Brit. colloq. something easy or pleasant (money for jam).
v.tr. (jammed, jamming) 1 spread jam on. 2 make (fruit etc.) into jam. jam tomorrow a pleasant thing often promised but usu. never forthcoming.
[ perh. = JAM(1) ]