Maybe if I can change tack completely....

Definitions are a good thing. Everyone knows what an inch is, and if they don't, then can get all metric about it and see that the SI has defined a Meter to be some fixed length, a centimeter to be 1/100 of a meter, and that an Inch is the same as 2.5something centimeters. Easy... We all can relate to an inch based on the definition of a meter.

RC hobbyists have very few true definitions... but some very concise terminology instead. A TX is not defined, but we all know what a TX is. People don't really know it, but RX's are also TX's (They transmit a signal to every servo ... even though it is not through "Radio" waves...). A more accurate name for the receiver would be "transducer". Anyway, I digress.

Flapperons is the term that was coined by people who used surfaces that are intended as Ailerons to be used part-time as flaps. Flapperons was a useful, unambiguous, and descriptive name. The ideal candidate for terminology.

Now, "flapperon" is being used to describe a significant modification to the use of the original mechanism involved. It is no longer a Flapperon when it has Elevators as part of the definition. It looses it's descriptive, and unambiguous nature, and thus it looses it's usefulness.

To give another analogy... the telephone. Telephone derives from the greek origin of "Te-le" which means "afar", and "phone" or phonic - meaning sound or voice. Telephone is a good example of a useful, descriptive, and unambiguous term. Now, along comes wireless technology... half the 1st world has a Cellular Telephone. Cellular Telephone is a very good descriptive, unambiguous name. The telephone works in Cells of reception. There is a BIG difference (socially) between a Cellular Telephone and a Telephone. People, being people, have made the names more concise to be more effective at communication, so, the Telephone has been abbreviated to just "phone", and, the Cellular Telephone has become a "Cellphone". Now, in a given context (yuppies in a bar), it has also been abbreviated to just "phone". BUT, although Cellphones are also telephones, the word "phone" does not DEFINE a cellphone. If you say "I have a Phone" then people have to contextualise the conversation... If you are sitting at a desk, they will assume that you have a normal phone. If you are in a pub, they will assume you have a Cellphone (unless it was the barman, in which case, it may or may not be the phone on the wall)..... sooo... the bottom line is that in the 3D circles (in the pub), you can talk about Flapperons to your hearts content, and people know that you actually mean "flapperons coupled with elevator in a special way". But, if you are in most other environments, people will fall back on the normal "definition" and assume that it is just ailerons as flaps, and any further "coupling" would have to be elaborated.

Bottom line.... Flapperons in any context means ailerons behaving like flaps. Also, in the 3D context, it may or may not mean that there is an Elevator mix with it.

Using it one way is absolute, and can be considered as close to a "definition" as you get. Using it in the "coupled with elevators" context opens up ambiguity.

So, you can not "redefine" flapperon any more than you can re-define telephone. No matter how much elevator you add, it will always be more correct to say "Flapperons coupled with elevator" than it will be to say just "Flapperons". There is nothing stopping you from making a new, more descriptive, useful, and unambiguous word for your new "toys". That is where words like "sailplane" (purpose built gliders) come from.

Go and be a pioneer of a new word that is useful, instead of trying (unsuccessfully) to recycle an old word as a definitive name for something else. There will be growling and gnashing of teeth all around if you continue to pollute the few "definitions" we do have!

All said lightheartedly...

gus