When I see a stamp listed on eBay as "mint no gum", for valuation purposes I assume it is "used". I would expand on Machaggis52's comment by dividing the categories into "mint", "mint hinged" (meaning original gum present but "hinged") and "used". The term "unused" is unclear. I interpret it to mean "mint no gum" or "uncancelled used" but I think some sellers use it to describe "mint hinged" stamps. The issue becomes complicated when the truly "used" stamps are more valuable than their "mint" counterparts. Perhaps the term "uncancelled no gum" should be introduced into the philatelic lexicon.
I take your point, but would like to expand a little. When one collects Germany, the difference in value between hinged and non-hinged can be immense, therefore, I do not buy hinged. The reason for my irritation in regard to EBay is that when the term 'mint' is used in the heading, if the item is of interest, I have to read the full listing to find 'hinged' in tiny
print in the final line. If people were obliged to state condition in the heading, it would save me, and others, a lot of time.