Answer from carrickflynn who originally used the term: "This is a squishy made-up term I am using only for this post that is sort of trying to gesture at a type of research that involves disentangling ideas and questions in a “pre-paradigmatic” area where the core concepts, questions, and methodologies are under-defined. (Nick Bostrom is a fantastic example of someone who is excellent at this type of research.)" https://forum.effectivealtruism.org/posts/RCvetzfDnBNFX7pLH/personal-thoughts-on-careers-in-ai-policy-and-strategy#rxAi3ssD8DtSHJtMG

Answer from Helen Toner: "structuring concrete agendas out of an amorphous blob of worries" https://twitter.com/Effect_Altruism/status/927219486201085957

Another possible answer (and an example of where the term is being used!): "What is needed in an early stage is disentanglement- structuring the research field, identifying the central questions, and clarifying concepts." https://forum.effectivealtruism.org/posts/oovy5XXdCL3TPwgLE/a-case-for-strategy-research-what-it-is-and-why-we-need-more

A comment to add to my OP: It seems like a really useful concept and I can imagine that having a central place that defines what disentanglement research is may be useful, and the concept generally becoming more known may also be useful, so that then people can easily reference that, and others will understand what someone means when they say a field needs disentanglement research or they're doing disentanglement research, people can share advice or host events focused on disentanglement research, funders can self-identify as funders interested in supporting disentanglement research in specific or various fields, etc.

Possible answer: It's taking a space and answering questions like – what's possible, what could & what should our goals be, main hypotheses and things that would inform what the best directions are, etc.