一直往下走，最终你会突然看到那条隐秘的瀑布。As you descend, suddenly you see at last the hidden waterfall.他把最隐秘的想法只告诉最好的朋友.He reveals his innermost feelings only to his best friend.地道的出口开在隐秘的地方.The exit of the tunnel is concealed....

“隐秘的”的英语可以翻译为：covert，dark，furtive，secret ...