It should be possible. There is something like that for WoW called Misspelled:
http://www.curse.com/addons/wow/miss...ther-downloads
It 's partly based on Hunspell:
http://hunspell.sourceforge.net/
It is just one hell of a workload to get that up and running.
The amount of time you have to spent on such an Addon to maintain it properly is insane
not saying that you have to get permission to get all these translations like these:
https://wiki.openoffice.org/w/index....s&oldid=199247
up and ready - and then modify them to include Game-Specific stuff as well.
Otherwise the Addon itself is quite useless if there isn't any proper Dictionary included.
I haven't checked the Addon itself, but if the author of Misspelled allows it to be ported (depends on the License under which it is released) it would be significantly easier, but still hard as the Dictionaries still would have to be properly modified for TESO and all the UI code would have to be rewritten for ESO as well.
Cheers!