extra
Definitions
Added to an existing or usual amount or number.
More than is due, usual, or necessary.
A person or thing added to something else, especially a performer in a film with no speaking part.
Examples
I have an extra ticket for the concert tonight if you would like to go.
The hotel charges an extra fee for guests who request a late checkout.
She put in some extra effort to ensure the project was completed on time.
Synonyms
additional supplementary spare surplus excess added auxiliary
Antonyms
essential necessary lacking insufficient needed required basic