noun. ['ˈɛmˈpiːˈeɪtʃ, ˈmaɪlzpɝˈaʊɝ'] the ratio of the distance traveled (in miles) to the time spent traveling (in hours).
noun. ['ˈɛmˈpiːˈeɪtʃ, ˈmaɪlzpɝˈaʊɝ'] a speedometer reading for the momentary rate of travel.