游泳圈英语说作"swimming ring"。它的来源是因为游泳圈是一个圆形的浮动装置，用于支持人在水中浮动。

以下是一些英文例句和中文翻译：

"Please make sure your child is wearing a swimming ring when they are in the pool." (请确保您的孩子在游泳池里穿着游泳圈。)

"The swimming ring is too small for me, can I get a larger one?" (游泳圈对我来说太小了，我能换一个大一点的吗？)

"The swimming ring provides buoyancy, making it easier to float in the water." (游泳圈提供浮力，使在水中漂浮变得更容易。)