<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>A scalar measure of the rate of movement of the object expressed either as the distance travelled divided by the time taken (average speed) or the rate of change of position with respect to time at a particular point (instantaneous speed).</n0:def-definition><n0:def-source>NCI</n0:def-source></n0:ComplexDefinition>