It was explained to me at the time but since then I have done a bit of Googling and in addition to the Wikipedia definition I have constructed one of my own.
A dewaniya is a reception area where a man receives his business colleagues and male guests. The term refers both to a reception hall and the gathering held in it.
It takes place in the evening in a special room or annex which is usually separate from the rest of a man’s house.
Only men are present and they sit around on soft benches or cushions, conversing casually, smoking, nibbling snacks and relaxing over beverages such as tea, coffee or the like.
Relatives and friends come and go throughout the evening. The host's job is to be hospitable and entertain his guests.
What topped off my visit on the last evening was to be taken to a dewaniya by Dahem Alqahtani (a friend of my host Bibi Alajmi). And I had a wonderful evening joining the other men in conversation. I was surprised how many had studied in England or were Manchester United fans :-)
It is a quite a fascinating idea and although not really a knowledge cafe - a great way to socialise and has got me thinking even more about the role of conversation in society. We need more opportunities and places to bring people together in conversation both in our business lives and our personal ones.
Bibi, Dahem, thanks for looking after me so well.