eonian

They made an eonian promise to stand by each other through every hardship.

用法提示：eonian 是形容词，作定语修饰 promise，表示“永恒的”。

The philosopher argued that human souls are not eonian, but mortal.

用法提示：eonian 在句中作表语，与 are 连用，表示“永恒的”。

As the waves kept crashing, she sensed an eonian rhythm in the ocean's song.

用法提示：eonian 作定语修饰 rhythm，表示“永久的”。