Exit velocity refers to the speed at which something, like a ball, leaves a particular area, such as a bat or a pitcher's hand. It measures how fast the object is moving when it is leaving that specific point. Full definition
Per Statcast he's producing an average exit velocity of 93.4 mph, which would've ranked second to Judge last season. (sbnation.com)
which I don't get... because Statcast has him on the first page of highest average exit velocity. (sbnation.com)
In its track mode, this setup had a higher exit velocity from the course's hairpin and allowed me to carry significantly more speed through the sweeping bends that follow. (cnet.com)