"挥剑而舞" can be translated as "dancing while wielding a sword" or more expressively as "swirling and dancing with a sword" to convey the dynamic and graceful movement of wielding a sword while dancing.
Here are two example sentences:
1、 The warrior performed a breathtaking dance, swirling and dancing with a sword in his hand.
（那位战士表演了一场令人惊叹的舞蹈，手中挥剑而舞。）
2、 In the ancient ceremony, performers would dance while wielding a sword, showcasing both their martial skills and artistic grace.
（在古老的仪式中，表演者会挥剑而舞，展示他们的武艺和艺术风采。）