ingredient

Compared meaning: a part that makes up a whole (noun).

比较义项：构成整体的一部分（名词）。

• element

  The broadest, most everyday word for one part of an abstract or physical whole (a design, a story, a chemical substance); often used with 'key' or 'essential'.

  语气最普通、适用范围最广，指抽象或具体整体中的一个部分（设计、故事、化学物质等），常与“关键的”或“基本的”连用。

  The design combines classic elements with a modern color palette.

  这个设计将经典元素与现代配色方案结合在一起。

• ingredient 本词

  Specific to substances combined to make food, or figuratively to one factor that contributes to a result; rarely used for physical parts outside cooking.

  专指用来制作食物而混合在一起的原料，或比喻性地指促成某种结果的因素；除烹饪外很少用来指物理部件。

  Fresh basil is the ingredient that gives this sauce its flavor.

  新鲜罗勒是让这道酱汁有独特风味的原料。

• constituent

  A formal, technical word for a part that makes up a compound, mixture, or structured system; sounds academic and is never used for food.

  语气正式、专业，指构成化合物、混合物或结构化系统的一部分；听起来较为学术化，从不用于食物。

  Sodium chloride is a common constituent of seawater.

  氯化钠是海水中常见的一种成分。

All three mean a part of a whole. Element is the broadest word, for parts of a design or substance. Ingredient is specific to food, or figuratively one factor in a result. Constituent is formal, for parts of a compound or mixture, not a voter.

这三个词都可表示“构成整体的一部分”，但适用范围和正式程度不同：element 最常用、范围最广；ingredient 专指食物的原料或比喻性因素；constituent 语气正式，多用于化学、混合物或结构化系统。这里不比较 constituent 表示“选民”的意思。