reciprocal

Definitions:

Alternate; mutually interchangeable.
- Etymological and pronouncing dictionary of the English language. By Stormonth, James, Phelp, P. H. Published 1874. (adjective) (adj.) (adjective)
In arith., the quotient resulting from the division of unity by any given number.
- Etymological and pronouncing dictionary of the English language. By Stormonth, James, Phelp, P. H. Published 1874. (noun) (n.) (noun)
Acting in return: mutual: given and received.
- The american dictionary of the english language. By Daniel Lyons. Published 1899. (adjective) (adj.) (adjective)
Mutual; done, given, or offered by each to the other; as, reciprocal benefits; offered in return for something done or given; as, reciprocal conditions; in grammar, showing action upon, or relation of, each to the other; as, reciprocal pronouns ( each other, one another).
- The Winston Simplified Dictionary. By William Dodge Lewis, Edgar Arthur Singer. Published 1919. (adjective) (adj.) (adjective)
That which is given or done by each to the other; the quotient obtained by dividing unity by a number.
- The Winston Simplified Dictionary. By William Dodge Lewis, Edgar Arthur Singer. Published 1919. (noun) (n.) (noun)
That which is reciprocal: ( math.) unity divided by any quantity.
- The american dictionary of the english language. By Daniel Lyons. Published 1899. (noun) (n.) (noun)
Mutual; given and received.
- The Clarendon dictionary. By William Hand Browne, Samuel Stehman Haldeman. Published 1894. (adjective) (adj.) (adjective)
Alternate; mutual; reflexive.
- Nuttall's Standard dictionary of the English language. By Nuttall, P.Austin. Published 1914. (adjective) (adj.) (adjective)
Reciprocally.
- The Winston Simplified Dictionary. By William Dodge Lewis, Edgar Arthur Singer. Published 1919. (adverb) (adv.) (adverb)
That which is reciprocal; the quotient that arises from dividing unity by a given number. Reciprocal ratio, the ratio between reciprocals of two quantities. Reciprocal terms, terms that have the same signification, and are mutually convertible.
- Nuttall's Standard dictionary of the English language. By Nuttall, P.Austin. Published 1914. (noun) (n.) (noun)

Usage examples:

You have this mutual and reciprocal knot in 1 John iv.
- The Works of the Rev. Hugh Binning by Hugh Binning
Probably Casanova struck the root of the matter in his remark, " Perfect accord is the first charm of a reciprocal friendship."
- The Memoires of Casanova, Complete The Rare Unabridged London Edition Of 1894, plus An Unpublished Chapter of History, By Arthur Symons by Jacques Casanova de Seingalt
The two accounts are too much at variance to enable the student to bring them into reciprocal agreement, yet that of Archer, being in the form of a diary, in which each day's transactions are noted, will be preferred to the narrative of Brereton, who wrote from recollection.
- Nooks and Corners of the New England Coast by Samuel Adams Drake