n. The act of listening or hearkening.n. In pathology, a method of distinguishing the state of the internal parts of the body, particularly of the thorax and abdomen, by observing the sounds arising in the part, either through the direct application of the ear to the adjacent external surface (immediate auscultation) or by applying the stethoscope over the part and listening through it (mediate auscultation). See stethoscope.