Definition of Bull

In ecclesiastical law. An instrument granted by the pope of Rome, and sealed with a seal of lead, containing some decree, commandment or other public act, emanating from the pontiff. Bull, in this sense, corresponds with edict or letters patent from other governments. Cowell; 4 Bl. Comm. 110; 4 Steph. Comm. 177, 179. This is also a cant term of the Stock Exchange, meaning one who speculates for a rise in the market.