reciprocal pronoun

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A pronoun or pronominal phrase, such as each other, that expresses mutual action or relationship.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun a pronoun referring to an antecedent in the plural, and expressing a mutual relation

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a pronoun or pronominal phrase (as `each other') that expresses a mutual action or relationship between the individuals indicated in the plural subject