Azizi,
'Fanny' is the female sex organ.

I remember working on security at the Sci-Fi Worldcon in Glasgow and taking in bags before people wandered the Art exhibits. I explained to several people that when we also asked that they 'check' their 'bum bags' it was what they might term 'fanny packs'. I also explained the difference in usage of 'fanny'

CHEERS
Nigel