guinea-pig

Noun

guinea pig (plural guinea pigs)

1. Any tailless rodent of the genus Cavia, which have short ears and superficially resemble large hamsters.
   1. (especially) A domestic guinea pig, Cavia porcellus, often kept as a pet.
2. (figuratively) A living experimental subject.
   • He became a human guinea pig and was paid by the company.

   Synonyms:

   lab rat

3. (dated, slang) A professional company director, without time or real qualifications for the duties.
4. (obsolete) A midshipman in the East India service; (by extension) a low-skilled or non-proficient seaman.
   • A good seaman he is... none of your guinea-pigs.1748, Tobias Smollett, The Adventures of Roderick Random, page 183