extendable

Extendable describes something that can be extended, lengthened, or augmented. In common usage it applies to physical objects, software systems, and abstract constructs that can be expanded beyond their initial scope.

The term comes from extend + able; from Latin extendere.

In hardware, extendable designs include telescoping arms, extendable ladders, and modular housings. In software, extendable systems expose extension points or plugin interfaces, allowing behavior to be added without modifying core code.

In programming, dynamic arrays and other growable containers are described as extendable when they can increase capacity. Memory management and amortized costs are considerations.

In mathematics and logic, extendability refers to the possibility of enlarging a structure or function to a larger domain or model. In design, extending a system raises tradeoffs between simplicity, performance, compatibility, and maintenance.

Common synonyms include expandable and extendible. See also extensibility.