Stethoscope

Steth″o‐scope (stĕth″ō̍‐skōp), n. [Gr. στη̑θοσ the breast + -scope: cf. F. stéthoscope.] (Med.) An instrument used in auscultation for examining the organs of the chest, as the heart and lungs, by conveying to the ear of the examiner the sounds produced in the thorax.