[1] : The Collaborative International Dictionary of English v.0.48

tank ship \tank ship\, tank vessel \tank vessel\ . naut.
   a vessel fitted with tanks for the carrying of oil or other
   liquid in bulk; -- called also tanker. a tank ship of very
   large capacity is called a supertanker.
   webster 1913 suppl. +pjc
see also:
tanker supertanker 

[2] : WordNet (r) 2.0

tank ship
     n : a cargo ship designed to carry crude oil in bulk syn: oil
         tanker, oiler, tanker
see also:
oil tanker oiler tanker 

Cruise Ship >> C Words
Cruise Ship, definition of term: Cruise Ship
cruise+ship_pag1.html

Clipper Ship >> C Words
Clipper Ship, definition of term: Clipper Ship
clipper+ship_pag1.html