The crossword solutions for the term 'TRIP TAKEN IN VAIN' are EGO, which is a three letter word. EGO is a term used IN psychology to refer to a person's sense of self-importance or self-esteem. It is often used to describe someone who is overly confident or has an inflated sense of their own importance. IN this context, a TRIP TAKEN IN VAIN could be interpreted as a journey that was TAKEN with the expectation of achieving something, but ultimately resulted IN nothing.