to step awkwardly while walking or running and fall or begin to fall

Running along the beach, she stumbled on a log and fell on the sand. 她沿着海滩跑步时绊到一块木头上摔倒了。

In the final straight Meyers stumbled, and although he didn't fall it was enough to lose him first place. 迈耶斯在最后的直道上绊了一下，虽然没有摔倒，但也足以使他丢掉第一的位置。

to walk in a way that does not seem controlled

We could hear her stumbling about/around the bedroom in the dark. 我们可以听到她摸黑在卧室里跌跌撞撞地走动。

He pulled on his clothes and stumbled into the kitchen. 他披上衣服，摇摇晃晃地走进厨房。

to make a mistake, such as repeating something or pausing for too long, while speaking or playing a piece of music

When the poet stumbled over a line in the middle of a poem, someone in the audience corrected him. 诗人在朗诵一首诗的过程中念错了一句，听众中有人纠正了他。

stumble across/on/upon something/someoneC2 偶然发现；撞见；邂逅

stumble into something 偶然开始做（某事）