Glad you enjoyed the quiz but I came here to find out why so many wrong answers were entered.
The clue said: "It is precisely defined by" BLACKWOOD (a popular bidding convention as noted by Kidas), so the answer was 'EBONY'.
thank you gen2 - I dread to think how many other wrong answers I had!! am neverthless looking forward to getting my sheet back. many thanks again for your hard work and the enjoyment it has given so many of us.