音标：[ә'pɒn]
prep. 在...之上, 迫近, 紧接着
在线英汉词典
upon的短语、例句：
upon
prep
1 (fml 文) = on2 1, 4b, 9, 10, 13.
2 (idm 习语) once upon a time => once. (almost) u`pon him, them, us, etc (of a time in the future) rapidly approaching （指将来的某一时刻）迅速接近
Christmas is almost upon us again. 圣诞节又快到了.
upon