The bulk update request #11130 has been approved by @evazion.
rename gloom -> gloom_(pokemon)
Currently we have three tags similar to 'gloom'; there's gloom (expression) which is the largest, gloom which is a character tag (of course), and gloomy which has 15 tags an a fantastic wiki. An alias from gloomy to gloom_(expression) was rejected 6 years ago in topic #12421.
I'd propose at least renaming gloom to gloom (pokemon), but I'm not sure what we'd like to do otherwise. In the previous topic someone mentioned "gloomy weather" but that seems vague at best and we already have tags like overcast, grey sky, cloudy sky, rain etc. that are more descriptive.
So we could either deprecate gloom and gloomy, alias the expression tag to one of them, alias one or both of them to the expression tag...