A definition is a doorway with a policy about who gets through.

Every definition determines who is inside and who is outside, and the boundary is a decision rather than a discovery. What counts as a resident, a disability, a full-time worker, a family. The definition looks technical and it is quietly distributing access to whatever depends on it.

When a definition affects real outcomes, look at who falls just outside it and what happens to them. Ask who wrote it and what they were optimising for. Arguments that appear to be about wording are frequently about eligibility, and it is worth knowing which one you are actually having.