It's more complicated than that. Words take on different meanings depending on the context.
From the wiki page: https://en.wikipedia.org/wiki/Americas
Since the 1950s,[19] however, North America and South America have generally been considered by English speakers as separate continents, and taken together are called the Americas, or more rarely America.[20][21][5] When conceived as a unitary continent, the form is generally the continent of America in the singular. However, without a clarifying context, singular America in English commonly refers to the United States of America.[5]
It's more complicated than that. Words take on different meanings depending on the context.
From the wiki page: https://en.wikipedia.org/wiki/Americas
Since the 1950s,[19] however, North America and South America have generally been considered by English speakers as separate continents, and taken together are called the Americas, or more rarely America.[20][21][5] When conceived as a unitary continent, the form is generally the continent of America in the singular. However, without a clarifying context, singular America in English commonly refers to the United States of America.[5]