From Longman Dictionary of Contemporary Englishstethoscopesteth‧o‧scope /ˈsteθəskəʊp $ -skoʊp/ noun [countable] 
MHan instrument that a doctor uses to listen to your heart or breathing
MHan instrument that a doctor uses to listen to your heart or breathingExamples from the Corpus
stethoscope• Apply a stethoscope to the Tory chest as he speaks.• It could've been any doctor, and it might not've been a stethoscope.• Putting on her stethoscope, she sounded his heart very carefully, then lifted his lips and looked at his gums.• She has with her his stethoscope, which she hands him.• In a normal labour intermittent auscultation with a Pinard stethoscope could not be regarded as an inadequate or negligent form of assessment.• Leaning against the Ping-Pong table, he picked up the stethoscope and felt its peculiar rubbery tubes.• Primo is sitting on the living room couch, listening to his own heart with the stethoscope.Origin stethoscope (1800-1900) French stéthoscope, from Greek stethos “chest” + French -scope 