Jeff Clark said:"Takes a good edge" means that you can get it very sharp. This does not require a high carbon content and does not mean that it holds that edge for a long time. There are hard stainless alloys that are very difficult to put a razor edge on. There are soft stainless alloys that are so inclined to form burrs that they are also hard to get to a razor edge.
Crayola said:Actually, I think it is a term with out much value.
You can take a bar of mild steel and sharpen it sharp enough to cut free hanging rope (Wayne Goddard wrote about that.) It will only cut once, but it will take an edge good enough to do that!