I don't know what does this phrase mean in English. Please explain it with some example sentences.
Well, I am a Chinese, so I think I can have a try.
"顺", means let it be, or just like the song from the movie Froze, let it go.
"其", means itself.
"自然", means what it means to be.
So, put it together, it means, just let it be what it should be, do not intervene. It usually used to comfort someone who just failed something.
I am an online Chinese tutor at iChineseLearning. Hope my answer will help you.As for your question: 顺其自然 is a Chinese idiom which literally means "(let things) follow the natural way." 顺 has the meaning of "to follow, to obey" 其 is traditional Chinese, has the same meaning as the modern Chinese phrase "他的，她的 or 它的". 自然 is nature.
Maybe this example can best tell its meaning: 我们已经努力了，能不能通过考试，只能顺其自然了。 translation: We have tried our best. Whether we can pass the exam，just let nature take its course.