The story
Blend of West + explaining, or West + -splain + -ing. Modelled after mansplaining. The term became popular in 2017.
First known use, by meaning
- from 2010s The act of condescendingly explaining something as a Westerner, especially sociopolitical views of Central and Eastern Europe and its historical and current relations with the Soviet Union and Russia.
Etymology from Wiktionary, CC BY-SA 4.0.