A custom that is peculiar to the United States or its citizens WordNet 3.0 & Open English WordNet

Americanism, also referred to as American patriotism, is a set of nationalist values which aim to create a collective American identity for the United States that can be defined as "an articulation of the nation's rightful place in the world, a set of traditions, a political language, and a cultural style imbued with political meaning". Wikipedia

An early 20th-century ideology frequently posited in opposition to communism or anarchism Wikipedia Disambiguation

A custom peculiar to the United States or the Americans. Wiktionary

Custom. Wiktionary (translation)