'Sea robber' definitions:

Definition of 'sea robber'

(from WordNet)
noun
Someone who robs at sea or plunders the land from the sea without having a commission from any sovereign nation [syn: pirate, buccaneer, sea robber, sea rover]

Definition of 'Sea robber'

From: GCIDE
  • Sea robber \Sea" rob"ber\ A pirate; a sea rover. [1913 Webster]