The term Amerind is a contraction of the words American and Indian. It was reportedly proposed at an 1899 Anthropology Society meeting as a shortened substitute to define "all the aboriginal tribes of the American continent and adjacent islands" (see the 1901 quotation). Sources use it in this general, all-encompassing sense for aboriginal groups from North America (see the 1905 quotation) to the equator (see the 1952 quotation) and further south.
This term should no longer be used as it carries negative undertones. The adjectival use, as in Aboriginal person or "indigenous person", is to be preferred.