In an answer to another meta question, hippietrail said:
For instance I strongly feel most tags including "word" are bad since they don't allow for idioms, set phrases, and other things we might think of as words but which are actually two or more words separated by spaces (echar de menos, nada que ver, etc). It's better to use "term" or just to leave out this part. Instead of "word usage" have either "term usage" or just "usage".
I was thinking about this, and I think that makes a lot of sense. It doesn't make sense to me for tags to always be differentiating between a single word, or a few words, or a phrase. If we want those distinctions (which I'd argue we don't), they should probably be separate tags (word, compound-word, phrase, etc.) rather than prefixes to many other tags.
Our word-usage tag is currently the 4th most used on the site, but the way it's named, it only applies to words. I'd propose renaming it to usage, so we can use it for usage questions about phrases or idioms or sentences too.