component 指一个整体的组成部分。
constituent 常可与component换用，指某一整体不可少的部分或成分。
element 指一个整体必不可少或固有的部分，强调一个复杂整体中最基本、最简单的元件、元素或成分等。
ingredient 普通用词，含义笼统。既可指混在一起而本身没有变化的物质，如配料，又可指与别的物质混在一起，发生了变化的成分。
参考例句
1. The atoms of one element differ in structure from those of every other element . 一种元素的原子结构不同于任何一种元素的原子结构。
2. An element means that stress discontinuity from one element to the next are inevitable. 意味着一个单元与近旁单元的应力不连续是不可避免的。
3. In this thesis, we analyze and design the piezoelectric device by finite element simulation. 本论文透过有限元素法对压电元件进行模拟与设计分析。
英英解释
n.
1. an abstract part of something
2. any of the more than 100 known substances (of which 92 occur naturally) that cannot be separated int
3. an artifact that is one of the individual parts of which a composite entity is made up; especially a
4. one of four substances thought in ancient and medieval cosmology to constitute the physical universe
5. the most favorable environment for a plant or animal
6. the situation in which you are happiest and most effective
7. a straight line that generates a cylinder or cone
