The term 'BEGIN A TRIP' can be summarized by two crossword solutions: SETOUT (6 letters) and SETOFF (6 letters). SETOUT is a verb meaning to start a journey or to leave on a journey, while SETOFF is a verb meaning to begin a journey or to start out on a journey. Both words are used to describe the act of starting a trip, but SETOUT implies a more organized and planned departure, while SETOFF implies a more sudden and unexpected departure.