I first happened upon the Economics version of the “Professor” series of these Social Sciences and Arts sites, each of which has the subject preceding Professor. They include:
Each of the different sites is of the same format, generally with terms categorized into theories and theorists, or their equivalent for the particular subject. Each of the terms is then defined, in a similar way to that in a dictionary or glossary of terms. The definitions are trawled from primary or secondary sources, and you can suggest amendments or additions.
There also tends to be a couple of useful links out from each site, be that to a discussion forum or online journals, etc.
These appear to be useful sites to students of the subjects, however, these aren’t my particular subject areas, so, as always, you’d need to assess them against other sources to validate accuracy.