groundage

from The Collaborative International Dictionary of English v.0.48

groundage \ground"age\ (ground"[asl]j), n.
   A local tax paid by a ship for the ground or space it
   occupies while in port. --Bouvier.
   [1913 Webster]

from Bouvier's Law Dictionary, Revised 6th Ed (1856)

GROUNDAGE, mar. law. The consideration paid for standing a ship in a port. 
Jacobs, Dict. h. t., Vide Demurrage.

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