what means EUC

If you're talking about This Listing, I'm sure he just fat-fingered the discription.

Then what should it be?

I can't even imagine, that designation doesn't appear anywhere else.

Considering this is a TMCC equiped loco, I suspect he's shorthanding "Electronic Uncoupling Control". It's about the only thing that makes sense.

Ebay has its own lingo.

EUC means "excellent, used condition".

HTH  (hope this helps)

LOL

I made a search and it's seems that it means excellent used condition, at first I tough it was a Lionel technology therm. 

Seems to be an echo in here.

Why in the world didn't he just say that in the listing?  FWIW, that's the first time I've ever noticed that term, and I've bought 100's of train goodies off eBay.

Abbreviated terms?  You might as well get used to it.  It's the twitter-tweeting language of the here-and-now generation.  It makes all the complaints about misspelling null and void, IMHO.  Anything goes as long as the INTENDED reader understands it.

BTW, it will be interesting to see how adroit our baristers (a.k.a., lawyers) are when they have to argue a term like "EUC" to a jury,...you know, is that what the letters meant, or did they mean 'Extraordinarily Upper Class', 'Essentially Useless Contraption', 'End Up Confused', etc....in trying to win a civil suit for damages, wrongful anything, etc., etc. 

I would think one of the most interesting, dynamic, crazy, confused, arguable, etc....albeit useless...fields of study nowadays would be etymology.  I'm sure there's a government grant, or two, lurking somewhere for the study thereof. 

Scrabble games are sure more argumentative...BOMPE.