:to move into position next to home plate in order to bat(靠近本垒)准备下一个击球 — often used figuratively in U.S. English在美国英语中常用作比喻
He finally stepped up to the plate [=he finally took action] and asked her to marry him.他终于采取行动,向她求婚了。
If you want this promotion, you're going to have to step up to the plate. [=you will have to improve your work performance to show that you deserve the promotion]如果你想得到提拔,就得有所作为。