Big fat mouth

As a detective trying to solve the mystery of the crossword clue ‘Big fat mouth’, my first thought was to consider words that relate to someone who talks a lot, such as “gab”, “yap”, “blabbermouth”, or “chatterbox”, or “mouth” can be associated with the idea of a trap, such as a mousetrap. And a “Big fat mouth” could imply a trap that is large or designed for bigger prey. With this in mind, I was able to come to the solution of ‘TRAP’. Through this thought process, I was able to unlock the mystery of the ‘Big fat mouth’ crossword clue and identify the correct answer as ‘TRAP’.