There is a slight distinction here though. I would tend to only describe the situation as a "shortage" if there is insufficient supply to meet demand at the actual price sellers are offering. If restaurants double their prices and thus a lot of people are no longer willing to pay (and are upset), that's not what I would consider a "shortage" (although it might certainly be described as such in headlines or in conversation). In my view that's no more a shortage than the ongoing lack of supply for private jets at the price of $10,000. I'd pay $10,000 for a private jet!

But there can also be a fuzzy area here. There may be situations where most sellers have not raised their prices to respond to decreased supply (for a variety of reasons), and therefore other mechanisms (like who gets in line the earliest) determine who gets to buy. At the same time there may be a small number of sellers who do raise prices (think of the toilet paper hoarders who resell on Craigslist at huge markups). If you consider that higher reseller price to be the "market price" then that wouldn't wouldn't strictly be a shortage, but if you consider the unchanged price to be the market price then that would indeed be a shortage. (In fact, this is why for every natural disaster there are articles with headlines like "Price gouging is actually a good thing; it's the solution to shortages.")