|baseball a hit that enables the batter to run round all four bases, usually by hitting the ball out of the playing area|
A highly successful achievement; also, doubling one's profits. For example, We scored a home run with that drug stock, buying it at 15 and selling at 30. This expression originated in the mid-1800s in baseball, where it refers to a pitched ball batted so far that the batter can round all three bases and reach home plate, scoring a run. Its figurative use dates from the mid-1900s.