Emily Dickinson Lexicon

AM'A-ZON, n. [This is said to be formed of α neg. and μαζος, breast. History informs us, that the Amazons cut off their right breast, that it might not incommode them in shooting and hurling the javelin. This is doubtless a fable.]

1. The Amazons are said by historians, to have been a race of female warriors, who founded an empire on the river Thermodon, in Asia Minor, on the coast of the Euxine. They are said to have excluded men from their society; and by their warlike enterprises, to have conquered and alarmed surrounding nations. Some writers treat these accounts as fables. – Herod. Justin.
2. By analogy, a warlike or masculine woman; a virago.
3. This name has been given to some American females, on the banks of the largest river in the world, who joined their husbands in attacking the Spaniards that first visited the country. This trivial occurrence gave the name Amazon to that river, whose real name is Maranon. Garcilasso, p. 606.