A community-led, open-source project attempting to define problematic language (in English) and suggest better replacement terms. Unfortunately, not all listed phrases or words have detailed breakdowns, but those that have do a great job of outlining the historical or cultural contexts that gave rise to the language in the first place, and why the modern usage is less than ideal (or not; some terms are deliberately listed for being positive), including sources or further reading.

Terms are also marked up with at-a-glance categorisation, such as cultural appropriation, racist language, or slur. Even if I don't 100% agree with some of the arguments presented (it skews American and therefore can lose or ignore some localised context), it's a brilliant resource for fact-checking, finding more inclusive language options, or just increasing awareness of the nuances involved.