“Reciprocal Pronoun: A term sometimes used for the compound pronouns each other and one another, which express a two-way interaction: Romeo and Juliet love each other/one another )Romeo loved Juliet and Juliet loved Romeo). In meaning, reciprocal pronouns contrast with reflexive pronouns: The Montagues and the Capulets loved themselves (The Montagues loved the Montagues, and the Capulets loved the Capulets). Reciprocal pronouns are, however, like reflexives in not normally being used as subjects: not They wondered where each other/one another was.”
Excerpted from: McArthur, Tom. The Oxford Concise Companion to the English Language. New York: Oxford University Press, 2005.