Following a recent discussion in chat and a year-old meta discussion, it seems to be best to get rid of the tag translation. The tag is broad and used in many different ways, so I find it pretty useless.
See the linked qestion for a list of several distinct ways the tag is used. We have more specific tags (translation-check, sentence-translation, motto, idiom, song-lyrics, …), but the tag translation is still very common.
Here is what the current plan is to do:
Create new tags english-to-latin and latin-to-english for the two most typical translation directions. (Rarer languages can maybe simply use a tag like french, but I prefer the format "X-to-Y-translation".)
Go through all translation questions and see if they need retagging (translations from Latin to English, the other direction can be left untouched). Some questions are best described by what is being translated (a verb, a name, a syntactical quirk, a conjunctive...), so no translation tag may be needed at all.
Change all tags translation to english-to-latin automatically (merge without synonymization), after having retagged those questions that ask for some other kind of translation. (This is our most common translation direction, so it saves some trouble not to retag all by hand.)
Create tag synonyms, e.g. english-to-latin-translation for english-to-latin, so that some appropriate tags are suggested when one starts typing "translation" in the tag box. (This is why we have the synonym single-word-translation for vocabulary.) In fact, the longer tag names are more descriptive, so I prefer to make them the main tags. The name of the main tag is easy to switch later with a couple of clicks.
Blacklist the tag translation to avoid it being recreated. We have already blacklisted grammar, and I think translation is very similar in breadth.
Does this sound reasonable? If there are no strong arguments against the operation, we will start executing it after about June 17. (Update: The due date has come and we are going forward with this.)
Are there tags related to translation we should add in this process? I'm sure some needs will be recognized along the way. For example, it's not clear whether we need a Greek translation tag of some kind (that wouldn't be covered by, say, greek and sentence-translation together).
Anyone is welcome to participate in the tag cleanup project, but let us first wait a couple of weeks (until June 17) in case there are reasons to plan more or drop the plan. If you edit old questions, please consider also making other improvements and try to limit yourself to about three edits per day. Every edit bumps the question to the front page, and we don't want to lose new questions in the flood of edited old ones. A tag merge (translation > english-to-latin) does not bump questions, which is one of the reasons I would merge the existing big tag with its most common "daughter".
If we want to rename the tags or introduce new synonyms later, that can be done with little effort. The goal here is to move to a more useful classification, whether the class names are final or not.