When you dial 911 from a fast food restaurant or sub shop because they screwed up your order or don't have what you want and you're too stupid to figure out how to handle the situation on your own.
The woman who dialed 911 because she couldn't get her Mcnuggets was having a Mcmergency
Meme emergency.
When you're in need of a specific meme you cannot find, forgot to save when you had the chance or while are on to go and don't have access to your meme folder.
Please help me Laura, I have a memergency! Send me the one with kermit in his car, going to get more tea!