I don't think the WT lets something silly like "word definitions" dictate to them !!
Like many cults, they have developed a whole lexicon of "Watchtower Speak" - and like most cults, they are constantly changing JW wordings so that you have to keep on your toes to know the latest terminology.
And by the way, according to thr Epistle of Barnabas, the shape of the cross was the greek leter "Tau" = T
There was a History Channel program about this - and they made a pretty strong case that the standard cross of the first half century A.D. may indeed have been a simple T shape without the small upright part. Maybe this will someday be acceptable to the JW world - after all one of their big objections was that the three arms might represent the trinity...(also JW B.S. as no ancient Roman was thinking about the trinity, of course).