Gain momentum is a phrase that is used to describe the process of increasing speed and intensity in order to achieve a desired goal. The term can be applied to many different situations, such as business, sports, or personal development. In this crossword, the solution for the term 'gain momentum' is 'ROLL, ' which is a verb that means to move forward by turning over and over on an axis. Rolling is often used as a metaphor for gaining momentum, as it implies a steady and continuous motion that can lead to success.