<p><strong>Noun</strong></p><ul><li>mutual relation of two or more things, parts, etc.: Studies find a positive correlation between severity of illness and nutritional status of the patients.</li><li>the act of correlating or state of being correlated.</li><li>Statistics: the degree to which two or more attributes or measurements on the same group of elements show a tendency to vary together.</li><li>Physiology: the interdependence or reciprocal relations of organs or functions.</li><li>Geology: the demonstrable equivalence, in age or lithology, of two or more stratigraphic units, as formations or members of such.</li></ul>