ADJ-GRADED （指颇具吸引力的人或地方）离经叛道的，反传统的 If you describe a person or place as louche, you mean that they are unconventional and not respectable, but often in a way that people find rather attractive. （指颇具吸引力的人或地方）离经叛道的，反传统的 [written]
...that section of London society which somehow managed to be louche and fashionable at the same time.