superflua

A false seam, and the most tempting kind: the parts are all real. Super is a live Esperanto preposition at rank 221, flui is a live verb at rank 795, and superflua looks exactly like super plus flua. Worse, the reading it produces - flowing over, more than the vessel takes - is almost exactly what the Latin word meant. This is a false seam that history very nearly endorses.

It is still false. Superflu- entered Esperanto as one borrowed unit, the way inspiri did on its own page, and the built form does not mean this. Glue super onto flua and you get something flowing above something else, a physical description with no judgement in it. Superflua is a judgement: it means unnecessary, one more than was wanted, and it is used of words, of luggage and of people.

Latin got there by the honest route. Superfluere was genuinely super plus fluere, so fluent, influence, fluid and superfluous are all the same water. The lesson is the one word building keeps repeating: a European root can carry a compound that was assembled in some other language centuries ago, and Esperanto inherits the meaning without inheriting the joinery.

In use. Superflue is the adverb, superfluo is a surplus, and superfluaĵo is a thing that is not needed. The everyday alternatives are worth having too: nenecesa for merely unnecessary, troa for excessive, and tro multe da when you simply mean too much of something.