noun
inside-the-park home run
Baseball term for a home run where the ball stays in play and the batter circles the bases without an error. Wasei-eigo from 'running home run'.
wasei-eigo (Japanese-coined English), from running home run
彼は足が速いので、ランニングホームランをよく打つ。
He's fast, so he often hits inside-the-park home runs.
外野手がもたつく間に、ランニングホームランになった。
While the outfielders fumbled, it turned into an inside-the-park home run.