An Americanism is a word, phrase or expression, commonly used in the United States, that has managed to escape from America to pollute the wider English language.
A completely online US political party. Promotes candidates through online videos, live webcasts and blog posts. Does not believe in "real world" activities like: debates, conventions, meetings or personal appearances of candidates.
A candidate of Americas Third Party just posted another video talking trash about Obama hoping it will go viral.
The spread to the rest of the world, particularly western nations, of the 'look at me' type of social behaviour perpetuated (and often glamourised) on US centrered social media. Examples can include when non US citizens use the American Constitution, FDA rulings, etc as a cornerstone for shaping their views on the internal goings on in their own countries, common crutch relied on by people many would consider 'conspiracy theorists' and others seeking validation through moral superiority.
"It's kind of sad how everyone is unfriending Ludwig" "Yes, his radical Americanisation has made him unbearable to be around. Who cares if the FDA has approved it or not? We live in Germany."
The attitude of American people to explain different cultures to the same people that culture belongs to, and the assumption that they are right despite never having actually setfoot on those people’s countries (or never having google it).
Americasplain is the dumb answer you receive in a polite conversation about your culture. You'l never know when it comes, but it's on its way.