"relax"的名词形式是 relaxation。以下是一些使用"relaxation"的例句：

1. Today's relaxation is becoming increasingly attractive to teenagers.

2. I'm going to spend the weekend just relaxing.

3. There'll be ample opportunity to relax, swim and soak up some sun.

这些例句展示了"relaxation"在不同语境下的应用，包括作为名词表示放松的活动或状态。