Extendible (adjective)

Able to be made longer or greater in size or amount.

Origin:

From the verb "extend" - to make something longer or greater in size or amount.

Examples:

1. The ladder is extendible, allowing the user to reach high shelves.
2. The warranty for the product is extendible for an additional fee.
3. The contract is extendible for an additional year.
4. The dress is extendible with a hidden zipper.
5. The table is extendible, allowing more guests to sit at the table.