a lack of enthusiasm, often because you have a lot of experience of life

There is an air of world-weariness and dejection about him. 他的神态中带着厌世和颓废。

He was staring at her with a world-weariness suggesting he'd heard her argument a hundred times. 他带着厌倦的神情盯着她——说明他已经听过无数次她的论点了。