passenger ship vs tow

passenger ship

noun
  • A ship whose primary function is to carry passengers. 

tow

noun
  • Something, such as a barge, that is towed. 

  • The short, coarse, less desirable fibres separated by hackling from the finer longer fibres (line). 

  • The act of towing and the condition of being towed. 

  • A rope or cable used in towing. 

  • Something, such as a tugboat, that tows. 

  • A speed increase given by driving in front of another car on a straight, which causes a slipstream for the car behind. 

  • An untwisted bundle of fibres such as cellulose acetate, flax, hemp or jute. 

verb
  • To aid someone behind by shielding them from wind resistance. 

  • To pull something behind one using a line or chain; to haul. 

How often have the words passenger ship and tow occurred in a corpus of books? (source: Google Ngram Viewer )