The crossword solution for the term BRAIN, MAYBE is NERD, which is a four-letter word. The term 'NERD' is used to describe someone who is highly intelligent and knowledgeable in a particular field, often to the point of being socially awkward. It is also used to describe someone who is passionate about a certain hobby or activity. The term has been around since the 1950s and has become increasingly popular in recent years.