lofty 的意思是seeming to think you are better than other people - used to show disapproval
例句:She has such a lofty manner.
superior的意思是thinking that you are better than other people - used to show disapproval
例句:She had that superior tone of voice.
两者都有“傲慢”的意思,差别更多在于搭配的对象和语法功能.lofty 一般作前置修饰语,例如lofty manner,lofty attitude 等等.superior则可以作表语表达“傲慢”的含义,例如feel superior to others等等.