guinea pig

Noun

• stout-bodied nearly tailless domesticated cavy; often kept as a pet and widely used in research

• a person who is subjected to experimental or other observational procedures; someone who is an object of investigation
  • the subjects for this investigation were selected randomly
    
  • the cases that we studied were drawn from two different communities
    

Related words

• Synonyms: 
  Cavia cobaya , subject , case