The word "superfluity" is correct and usable in written English.
You can use it to describe something that exceeds what is necessary or normal. For example: "The superfluity of candy in his room was staggering."
If Noguchi sculptures seemed superfluous on the pond in the Hill-and-Pond Garden, that superfluity called attention to the carefully placed bridges, temples, and specimen trees already there.
There is also a superfluity of stop signals.
There is no denying, though, that the superfluity could have been better handled, and that the poor freezing wretches immobilised outside deserved better.Inside, temperature and stasis are not a problem; things are simply slower.
The overhaul, led by Mr Detter, exposed the superfluity of many SOE subsidiaries and other holdings, spurring the government to put three times more under the hammer than the nominally more privatisation-friendly previous administration had done.All of which points to a huge opportunity for governments to sell or sweat more assets, and by doing so reduce fiscal stress.
The function of the music was, in the words of the foreword to Alceste, "to serve poetry by means of expression and by following the situations of the story, without interrupting the action or stifling it with a useless superfluity of ornaments".
The seeming superfluity of orchestral resource he called for, especially in the later symphonies, is handled with restraint and sensitivity Mahler was a conductor as well as a composer and knew well the capabilities of the instruments.
Whatever the justification for such assertions, it must nevertheless be recognized that neither of these authors suggests that aesthetic appeal or art are synonyms for superfluity.
The ancient Greek philosopher Democritus explicitly denied any fundamental need for music: "For it was not necessity that separated it off, but it arose from the existing superfluity".
Before Botticelli, tondi had been conceived essentially as oblong scenes, but Botticelli suppressed all superfluity of detail in them and became adept at harmonizing his figures with the circular form.
Pan-fried wild halibut was sweet and moist, and the accompanying shredded celeriac danced along with tiny St George mushrooms; the only bum note was a superfluity of lobster foam.
