One such word is "aluminium", the pronunciation of which has left a number of my American friends bewildered on the spot, since the standard American equivalent famously drops the final "i" to spell out "aluminum."
Indeed, I too was a little befuddled upon hearing the latter spoken for the first time: my initial impression, as a Brit, was that the word "aluminum" was probably some sort of Star Trek reference with which I was not familiar (I pictured some new captain taking command of The USS Aluminum).
But after both myself and the Americans I may have been speaking to dusted off our respective brains, sat down, and breathed for a moment, we came to the realization that the two pronunciations both meant the same thing: a non-soluble chemical element with the internationally recognized periodic symbol Al.
So why do Americans pronounce it "Aluminum"?
British prescriptivists - that is, Brits who do not welcome change to the language - would tell you that the U.S. respelling owes much to "American arrogance"; that it is just another example of "the Yanks needlessly simplifying the language". However, just a cursory amount of research into the matter will tell even the most ardent linguistic conservative that the matter is not quite that simple.
It all began, apparently, when an indecisive British chemist by the name of Sir Humphrey Davy in fact coined the now archaic word "alumium" in 1808. However, referring to the element in his 1812 book Elements of Chemical Philosophy, he would use the word "aluminum", much as Americans do today.
It was British scientists of the time, however, that decided, with a beautiful level of verbosity, that: “Aluminium, for so we shall take the liberty of writing the word, in preference to aluminum, which has a less classical sound.”
Be that as it may, scholars in both countries continued to use both variants of the word throughout the early 1800s, only for the industrial boom - and the onset of mass production - to bring the word to national attention (it had largely only been used within science circles initially).
Devising a new, inexpensive method for producing the metal in 1892, American chemist Charles Martin Hall opted to incorporate the "aluminum" variant - which had gained popularity following its inclusion in the 1828 Webster's Dictionary - on his advertising literature, despite having used "aluminium" on all of his patents. It could be argued, then, that "aluminum" in fact remained in the American vernacular quite by accident, if it is to be believed that the variant used in his advertising materials was nothing more than a typo.
"Aluminum" would later be accepted as the official spelling by the American Chemical Society, and though the International Union of Pure and Applied Chemistry officially recognizes "aluminium", its American counterpart is accepted as an alternative.
History aside, part of me still prefers to imagine a group of Klingons storming the bridge of USS Aluminum. Perhaps this notion will prove, during debates about the word's history, a far more concise, if inaccurate, explanation.