stick in the mud 顽固，老古板，墨守成规

【例句】
How will metropolis elites of the modern society stick in the mud and be willing to live unromantic living?
作为现代社会中坚力量的都市精英岂能墨守陈规、甘于平淡的生活？

My dad is such a stick in the mud；he never wants to leave the house.
我爸爸真是个老古板，他从来没想要走出家门。