Brown billBrown" bill`\ [Brown + bill cutting tool.] A bill or halberd of the 16th and 17th centuries. See 4th Bill. Many time, but for a sallet, my brainpan had been cleft with a brown bill. --Shak. Note: The black, or as it is sometimes called, the brown bill, was a kind of halberd, the cutting part hooked like a woodman's bill, from the back of which projected a spike, and another from the head. --Grose.