Definify.com
Webster 1913 Edition
Drumhead
Drum′headˊ
,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.)
, 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.