the name given to a sheep bred by British scientists in 1997. The sheep was a clone (= an exact copy) of another sheep, and was the first clone to be made by using cells taken from another adult animal. Many people think that the technology of cloning will lead to important new benefits for farming, medicine and other areas of life. Others are worried because they think the technology will not be used wisely, or that clones of people might be created. Dolly died in 2003.