The term 'grilling order' refers to the order in which food is cooked on a grill. The four-letter solution for this term is 'TALK'. This is an acronym for the steps of grilling: temperature, arrangement, location, and kindling. Temperature refers to the heat of the grill, arrangement is the placement of the food on the grill, location is the distance from the heat source, and kindling is the type of fuel used.