This term is defined in the dictionary.

He defined the project's objectives with precision.

The definite article is used to indicate a specific object.

I am defining the project.

This concept is definable in a few words.

The definable limits of this concept are clear.

By definition, this process is infallible.

The definite integral of the function is equal to the sum of the areas of the rectangles.

The definer of this word is very clear.

Ultimately, everything went well.