reserve
Definitions
To refrain from using or disposing of something, keeping it for a future time or a specific purpose.
A supply of a commodity not currently needed for immediate use but available if required.
A formal feeling of restraint or self-restraint in one's manner or expression.
Examples
I would like to reserve a table for two at the restaurant tonight.
The nature reserve is home to many endangered species of birds.
She has a quiet reserve that makes it difficult to know what she is thinking.