Definify.com
Webster 1913 Edition
Webster 1828 Edition
Tunnage
TUN'NAGE
,Adj.
  1.
  The duty charged on ships according to their burthen, or the number of tuns at which they are rated.2.
  A duty laid on liquors according to their measure.3.
  A duty paid to mariners by merchants for unloading their ships, after a rate by the tun.4.
  The whole amount of shipping, estimated by the tuns.