internationalize v.

1780, coined by Jeremy Bentham from inter- "between" + national (adj.). In the phrase international jurisprudence. He footnotes the word with:

The word international, it must be acknowledged, is a new one; though, it is hoped, sufficiently analogous and intelligible. It is calculated to express, in a more significant way, the branch of law which goes commonly under the name of the law of nations: an appellation so uncharacteristic, that, were it not for the force of custom, it would seem rather to refer to internal jurisprudence. [Bentham, "Introduction to the Principles of Morals and Legislation"]

As a noun and with a capital -i-, it is short for International Working Men's Association, a socialistic worker's movement with global aims, the first chapter of which was founded in London by Marx in 1864. The group lends its name to "The Internationale" (from fem. of French international, which is from English), the socialist hymn, written 1871 by Eugène Pottier. International Dateline is from 1882. Related: Internationally (1821).

word-forming element used to make verbs, Middle English -isen, from Old French -iser/-izer, from Late Latin -izare, from Greek -izein, a verb-forming element denoting the doing of the noun or adjective to which it is attached.

The variation of -ize and -ise began in Old French and Middle English, perhaps aided by a few words (such as surprise, see below) where the ending is French or Latin, not Greek. With the classical revival, English partially reverted to the correct Greek -z- spelling from late 16c. But the 1694 edition of the authoritative French Academy dictionary standardized the spellings as -s-, which influenced English.

In Britain, despite the opposition to it (at least formerly) of OED, Encyclopaedia Britannica, the Times of London, and Fowler, -ise remains dominant. Fowler thinks this is to avoid the difficulty of remembering the short list of common words not from Greek which must be spelled with an -s- (such as advertise, devise, surprise). American English has always favored -ize. The spelling variation involves about 200 English verbs.