Extensibility
The Century Dictionary and Cyclopedia
noun.
The quality of being extensible: as, the
extensibility
of a fiber or of a plate of metal.
the GNU version of the Collaborative International Dictionary of English
noun.
The quality of being extensible; the capacity of being extended.
Wiktionary, Creative Commons Attribution/Share-Alike License
noun.
The
capability
of being
extended
noun.
A
quality
of
design
that takes possible future advances into consideration and attempts to
accommodate
them