Anything (such as a piece of furniture, or a software feature) that is built in, not added as an extra.
Being an essential and permanent part of something.
Being an included feature that normally comes as an extra.
Constructed as a non-detachable part of a larger structure.
An object within a user interface to which a certain action or transformation (i.e., verb) is applied.
A word that functions as the name of a specific object or set of objects, such as person, animal, place, thing, phenomenon, substance, quality, or idea; one of the basic parts of speech in many languages, including English.
To convert a word to a noun.