lab rat

plural lab rats · alternative lab-rat

1. A rat used in a laboratory for scientific experiments.

   Synonyms: guinea pig

2. idiomaticA student or employee who spends a great deal of time working in a laboratory.

   As a graduate student, she loved being a “lab rat,” Dr. Blackburn said, adding, “I was just really focused on the science, the science, the science.”

   2013 April 8, Denise Grady, “Profiles in Science: Charting Her Own Course”, in New York Times, retrieved 20 Apr 2015

3. idiomaticA person or group used as the subject of an experiment or test, especially unwillingly or unwittingly.

   This time, Vincent . . . became an unwitting lab rat for a vaccine that turned soldiers into hyperaggressive killing machines.

   2012 September 13, “TV Review: ‘Beauty and the Beast’”, in Washington Post, retrieved 20 Apr 2015

   2 more examples

   Tests were done on me that you can't even imagine. For years. Cerberus did them. They tortured me. They used me as a damn lab rat. And now you're teaming up with them like they're any other merc band?

   2010, BioWare, quoting Toombs, Mass Effect 2 (Science Fiction), Redwood City: Electronic Arts, →OCLC, PC, scene: What the hell?

   Looking back at the unprecedented meddling of European powers in his country's politics amid the Euro crisis — a series of events that led to his fall as well as Greece becoming the first country in the zone to be forced to accept painful austerities in exchange for bailout loans — Papandreou told TIME, "I think it couldn't have been avoided. We were a lab rat, an experiment."

   2012 May 1, Joanna Kakissis, “Greece's Former Prime Minister Assesses the State of His Nation”, in Time, retrieved 20 Apr 2015