The term DECIDE OFFICIALLY can be summarized as the act of making a decision in an official capacity. This decision is usually made by someone in a position of authority, such as a judge or a government official. The crossword solution for this term is RULE, which implies that the decision is made according to a set of rules or regulations. Therefore, DECIDE OFFICIALLY can be defined as the act of making a decision in an official capacity according to a set of rules or regulations.