1. (baseball) a measure of a pitcher's effectiveness; calculated as the average number of earned runs allowed by the pitcher for every nine innings pitched; [syn: earned run average, ERA]
WordNet (r) 3.0 (2006):
earned run average
n 1: (baseball) a measure of a pitcher's effectiveness;
calculated as the average number of earned runs allowed by
the pitcher for every nine innings pitched [syn: earned
run average, ERA]