@johas @fsfe I wouldn't define it; it's the first time I hear this term. Taken literally, it would mean proprietary software that claims to be open source, but I have never heard of such a thing (other than people forgetting to include a LICENSE file on GitHub in small new projects, but a bug report solves it).
Overall, the claim that "OpenWashing has become a growing issue in the Free Software community" seems to be really silly because no definition I can think of can make this claim true.
@elgregor @fsfe This is exactly one of the questions where we'd really appreciate your input: How would you define it? You can use this form to leave your input: https://share.fsfe.org/apps/forms/s/Z6xHfa8EiXk77FFreg2R6A6T