Is there any way to create an exception for the minimum answer length for questions tagged "single-word request?" It seems wasteful and inconvenient and seems feasible from a coding perspective.
Simply link the word to its dictionary definition. Observe:
This pushes your answer over the 30-character limit and makes it considerably more helpful, as the OP might not know that word. In fact, that might be the very reason why he's asking for it in the first place. And even if he does recognize it, other/future readers might not.
Edit: the site engine has since been changed such that URLs no longer count towards reaching the character limit. What I recommend now is that you quote the relevant dictionary definitions.
Of course the link should still be included as well, in fact now even more so than before, because otherwise it's not clear where your quote is from.
There should be no exception to cover such cases. The fact the request is for a single word doesn't mean the answer must be phrased using a single word.
I would expect an answer to a single-word request to describe why the proposed word suits the request.
And at the very least, you can always reply with "The word you are looking for is Goshealm," for example.