Wordnet 3.0
NOUN (2)
1. 
 the fee charged for carrying goods in lighters; 
2. 
 the transportation of goods on a lighter; 
The Collaborative International Dictionary of English v.0.48:
Lighterage \Light"er*age\ (l[imac]t"[~e]r*[asl]j; 48), n.
   1. The price paid for conveyance of goods on a lighter.
      [1913 Webster]
   2. The act of unloading into a lighter, or of conveying by a
      lighter.
      [1913 Webster]
WordNet (r) 3.0 (2006):
lighterage
    n 1: the fee charged for carrying goods in lighters
    2: the transportation of goods on a lighter