the quality of not changing as the years go past, or as fashion changes

She obviously chose these tracks for their timelessness, their ability to transcend generations. 很显然她选择这些曲目是因为它们是经典的传世之作。

The figure in the painting looked out at the world with a serene timelessness. 画中人物以宁静永恒的目光注视着世界。