The crossword solution for the term LEAD-IN TO MANIAC is 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 arrogant. In the context of the term LEAD-IN TO MANIAC, it could be referring to someone who is on the brink of becoming a maniac due to their inflated EGO.