前传的英文：
prequel

参考例句：

He traveled homeward through a region made barren by drought and dust storms. On the way he met Jim Casy an expreacher.
他穿过一片由干旱和沙暴造成的荒凉不毛的地区。在旅途中，他遇到了吉姆·凯西，一名前传教士。

prequel是什么意思：
n. (据已问世文艺作品的情节凭想象上溯创作的)先行篇, 前篇
前传

a prequel that featured the characters of the famous novel in their youth.
描述著名小说中青年期的先行篇

When the opening weekend of the prequel movie Star Wars: Episode 1--The Phantom Menace was planned in the US, crazy fans queued up to buy tickets simply to see the preview trailer.
当前传影片《星球大战：第一集－－幽灵的威胁》在美国首映的那个周末被列入计划时，疯狂的影迷排起长队买票就是为了看一眼电影的宣传预告片。