Other forms: americans
American means belonging to the United States, or to a person from it. American English, an American accent, she is American.
There is a genuine ambiguity worth knowing: strictly the Americas are two continents and an American could mean anybody from Canada to Chile, and speakers of Spanish and Portuguese often object to the narrower use. In practice English uses American for the United States and says South American, Latin American or North American when it means the wider thing. The word always takes a capital letter, and there is no separate noun form — an American is both the person and the adjective.
1adjectiveamericanBelonging to the United States.
“It is an American company with a British name.”
2noununitedSomebody from the United States.
“Two Americans were staying at the same hotel.”
3adjectivecontinentsBelonging to the continents of America.
“The South American route was the longer one.”
Too few real examples of this word to estimate which sense is commonest.
american is a nationality.
American comes from America + -n. From America + n. Compare NL. amerī̆canus.
Etymology from Wiktionary, CC BY-SA