Maybe playwith will fix their overzealous censorship right? Haha.
Unzip client_mod/DownloadedResources.zip and replace the exiting DownloadedResources.dat file in TERA\TERA-CLIENT\S1Game\S1Data. You may wish to make a backup of the original, but if you want a fresh copy of the original file you can just delete it and the launcher will download a new one.
Automically on by default. Or you can activate it manually with /8 gab on. Only decensors words in the filter list found in data\censored_words.json