ABCDEFGHIJKLMNOPQRSTUVWXYZ Definition of PM more ... The half of the day from Midday to Midnight. What we call afternoon and evening. It comes from the Latin "Post Meridiem" for "after midday". ../measure/images/time-am-pm.js See: AM, Twelve-Hour Clock, Twenty-Four Hour Clock, Time The Time - Converting AM/PM to 24 Hour Clock