手背后用英语怎么说

手背后的英文短语是"back of the hand"。它的来源可能是因为手背后指的是手掌正面所对应的背面，如同身体背面对应身体正面一样。
例句：
She felt the back of her hand to check her temperature. 她用手背摸了摸额头，检查体温。
He slapped her across the back of the hand. 他用手背打了她一巴掌。
The back of the hand is often used to test the temperature of food. 手背常用于测试食物的温度。