To convoke is "to call to a meeting," specifically one that is formal. There is no fun to be had when you're convoked; there is serious business to attend to.
Convoke emerged in the 14th century, from the Latin word convocare — "to call together;" the definition stands today unchanged. Use convoke when you are speaking of people or a group being summoned for an official gathering, like the kind the government or a large organization holds.
