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.
[written]
...that section of London society which somehow managed to be louche and fashionableat the same time.
louche in British English
(luːʃ)
adjective
shifty or disreputable
Word origin
C19: from French, literally: squinting
louche in American English
(luʃ)
French
adjective
[also in roman type]
questionable; shady; odd
Word origin
Fr, lit., squinting < L lusca, fem. of luscus, one-eyed
Examples of 'louche' in a sentence
louche
This one is expected to host a rather more louche clientele.
Times, Sunday Times (2012)
They have to win something and they are prepared to leave the louche life behind.
Times, Sunday Times (2008)
This has a rather louche red interior, which clashes somewhat with the maroon shirts of the waiters.
Times, Sunday Times (2007)
He was a pretty louche character, exactly the sort of toff who became involved in this practice.
Times, Sunday Times (2008)
The exhibition is an intriguing throwback to another era: a world of louche nightclubs, obliging hostesses and champagne all round.
Times, Sunday Times (2010)
He had hoped to be a literary writer, moving around on the festival circuit, enjoying a louche and contemplative lifestyle.