zeal / enthusiasm 这两个名词均含“热情”之意。
zeal: 是不可数名词
通常指为实现向往的事业或为达到所追求的目标而积极投身到实践活动中所表现出来的热情。
在《柯林斯高阶英汉双解学习词典》中的解释：不可数名词，意为“热情;激情;热忱”，英文释义： Zeal is great enthusiasm, especially in connection with work, religion, or politics.例如：
Mr Lopez approached his task with a religious zeal. 洛佩斯先生以宗教般的热诚对待工作。
They worked with great zeal to finish the project. 他们热情高涨地工作, 以期完成这个项目。
enthusiasm: 是个可变名词，即可以作可数名词，也可以作不可数名词
侧重指比较理智的热情，如对人对事的钦佩或为了事业或目的等所表现出的追求与忠诚。
在《柯林斯高阶英汉双解学习词典》的解释为：
1.不可数名词，意为“热爱;热情;热心;积极性”， 英文释义： Enthusiasm is great eagerness to be involved in a particular activity which you like and enjoy or which you think is important. 例如：
The lack of enthusiasm for unification among most West Germans fills him with disappointment. 大多数西德人都没有渴望统一的热情，这令他无比失望。
Their skill, enthusiasm and running has got them in the team. 他们的技术、热忱和跑动能力使他们得以加入这支球队。
The speech aroused the enthusiasm of the students. 那篇演说唤起了学生们的热情。
2.可数名词，意为“感兴趣的活动；热衷的学科；热衷的事物” ，英文释义：An enthusiasm is an activity or subject that interests you very much and that you spend a lot of time on.例如：
Draw him out about his current enthusiasms and future plans. 让他畅所欲言地谈谈自己目前热衷的活动和将来的计划。
One of his many enthusiasms is a great fondness of eastern music. 酷爱东方音乐是他众多爱好之一。
3.可数名词，意为“激发热情的事物(或人)；所热衷的事物；酷爱的事物(或人)”，例如：
During the last 20 years, enthusiasm for musicals have developed in new places. 在最近的20年, 醉心于音乐的人已找到有新的地方。