element

An artifact that is one of the individual parts of which a composite entity is made up; especially a part that can be separated from or attached to a system.

“a component or constituent element of a system”

Any of the more than 100 known substances (of which 92 occur naturally) that cannot be separated into simpler substances and that singly or in combination constitute all matter.

An abstract part of something.

“the grammatical elements of a sentence”

A straight line that generates a cylinder or cone.

One of four substances thought in ancient and medieval cosmology to constitute the physical universe.

“the alchemists believed that there were four elements”

The most favorable environment for a plant or animal.

“water is the element of fishes”

The situation in which you are happiest and most effective.

“in your element”