Here's a link to a recent question entitled, "Electronegativity of Potassium (Pauling)". The OP tagged the question under "Resources" and writes, "Sorry for the lack of tags, I don't know under what tags I could throw this question." There have also been some other recent questions (pKa of HX acids) where an "Electronegativity" tag would have been useful.
I have created electronegativity. I think it definitely deserves its own tag. I did not search for those other questions, so if you happen to come across one, please retag if it's appropriate.