The Collaborative International Dictionary of English v.0.48:

internationalisation \internationalisation\ n.
   the act of bringing something under international control.
   [Chiefly Brit.]

   Syn: internationalization.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

internationalisation
    n 1: the act of bringing something under international control
         [syn: internationalization, internationalisation]

The Free On-line Dictionary of Computing (30 December 2018):

internationalisation
globalisation
i18n
internationalization

    (i18n, globalisation, enabling, software
   enabling) The process and philosophy of making software
   portable to other locales.

   For successful localisation, products must be technically
   and culturally neutral.  Effective internationalisation
   reduces the time and resources required for localisation,
   improving time-to-market abroad and allowing simultaneous
   shipment.  In orther words, internationalisation abstracts
   out local details, localisation specifies those details for a
   particular locale.

   Technically this may include allowing double-byte character
   sets such as unicode or Japanese, local numbering, date and
   currency formats, and other local format conventions.

   It also includes the separation of user interface text
   e.g. in dialog boxes and menus.  All the text used by an
   application may be kept in a separate file or directory, so
   that it can be translated all at once.  User interfaces may
   require more screen space for text in other languages.

   The simplest form of internationalisation may be to make use
   of operating system calls that format time, date and
   currency values according to the operating system's
   configuration.

   The abbreviation i18n means "I - eighteen letters - N".

   (1999-06-28)