Eigenquestions
A framing technique that identifies the one question whose answer likely resolves a cascade of subsequent questions as well.
Origin
Coined by Shishir Mehrotra and Matt Hudson while they worked together at YouTube, and later refined at their company Coda. The name borrows from the linear-algebra concept of eigenvectors — from the German eigen, meaning "own" — which identify the most discriminating direction in a multidimensional space, just as an eigenquestion isolates the single choice that resolves many downstream decisions.
Everyday Use
Framing a problem so often starts with ensuring you're asking the right question. 100 mediocre questions are often less valuable than one single question that provides you with not only the correct/helpful response, but with a question that frames the nature of the problem in the right way.