To move or to stop wasting time. Back in the 1920s and '30s, taxi dancers were female dance hall employees whose livelihood was dancing with any men who paid for the opportunity. The usual fee was ten cents, but that's not what “dime” in “get off the dime” meant. Dancing with man after man for hours on end was tiring business, and the women often draped themselves over their partners and moved their feet as little as possible, no more than the width of a dime. Although the men didn't object, dance hall managers did. That sort of mobility might lead to hankypanky that would invite attention from the police and other enforcers of public morality. “Get off the dime” was the order, whereupon the women were then obliged to take more energetic dance steps.