packet-boat vs vessel

packet-boat

noun
  • Passenger boat. 

  • River or canal boat that carries mail. 

  • Government-commissioned mail ship. 

vessel

noun
  • Any craft designed for transportation on water, such as a ship or boat. 

  • A craft designed for transportation through air or space. 

  • A container of liquid or other substance, such as a glass, goblet, cup, bottle, bowl, or pitcher. 

  • A tube or canal that carries fluid in an animal or plant. 

  • A person as a container of qualities or feelings. 

verb
  • To put into a vessel. 

How often have the words packet-boat and vessel occurred in a corpus of books? (source: Google Ngram Viewer )