The phrase "to grow this movement" means to make the movement larger, stronger, and more influential by attracting more people to join and support it. Full definition
Take, for example, the new, growing movement in Christian hip - hop. (relevantmagazine.com)
Over 1,300 activists from around the world came together for the three - day event to learn how to spread the truth about the climate crisis and grow the movement for solutions. (climaterealityproject.org)
Join the rapidly growing movement to end shame, guilt, and poor self - esteem related to the failures of dieting. (drconason.com)