1) Musical membrane 2) Summary 3) The top part of a capstan 4) Timpani surface 5) Unofficial 1) Summary 2) Unofficial 
[sign] The term drumhead refers to a type of removable sign that was prevalent on North American railroads of the first half of the 20th century. The sign was mounted at the rear of passenger trains, and consisted of a box with internal illumination that shone through a tinted panel bearing the logo of the railroad or specific train. Since ...
• (n.) The top of a capstan which is pierced with sockets for levers used in turning it. See Illust. of Capstan. • (n.) The parchment or skin stretched over one end of a drum.
1. The parchment or skin stretched over one end of a drum. ... 2. The top of a capstan which is pierced with sockets for levers used in turning it. Drumhead court-martial, a summary court-martial called to try offenses on the battlefield or the line of march, when, sometimes, a drumhead has to do service as a writing table. ... Source: Websters Dic...
Drum'head` noun 1. The parchment or skin stretched over one end of a drum. 2. The top of a capstan which is pierced with sockets for levers used in turning it. See Illust. of Capstan . Drumhead court-martial (Mil.) , 
[adj] - performed speedily and without formality 2. [n] - a membrane that is stretched taut over a drum
summary adjective performed speedily and without formality; `a summary execution`; `summary justice`
the membrane stretched upon a drum. · the top part of a capstan.