very dark wood of any of several blackwood trees
any of several hardwood trees yielding very dark-colored wood
any of several trees yielding a very dark wood
African blackwood (Dalbergia melanoxylon), of Africa
Any of many places in England, Scotland and the United States.
A bidding convention in contract bridge, used to explore the partnership's possession of aces, kings and in some variants the queen of trumps, to judge more precisely whether slam is likely to be a good contract.