reciprocal

EnglishEdit

Latin reciprocus, possibly from a phrase such as reque proque (“back and forth, to and fro”), from re- (“back”), prō (“forwards”) and -que (“and”).

reciprocal (not comparable)

Of a feeling, action or such: mutual, uniformly felt or done by each party towards the other or others; two-way.
reciprocal love; reciprocal duties
- c. 1603–1606, William Shakespeare, “The Tragedie of King Lear”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, →OCLC, [Act IV, scene vi]:
  Let our reciprocal vows be remembered.
Mutually interchangeable.
- 1725, Isaac Watts, Logick: Or, The Right Use of Reason in the Enquiry after Truth, […], 2nd edition, London: […] John Clark and Richard Hett, […], Emanuel Matthews, […], and Richard Ford, […], published 1726, →OCLC:
  
  These two rules will render a definition reciprocal with the thing defined.
(grammar) Expressing mutual action, applied to pronouns and verbs; also in a broad sense: reflexive.
(mathematics) Used to denote different kinds of mutual relation; often with reference to the substitution of reciprocals for given quantities.
Done, given, felt, or owed in return
a reciprocal invitation to lunch

done by each of two people towards the other

Arabic: مُتَبَادَل‎ (mutabādal)
Belarusian: узае́мны (uzajémny)
Bulgarian: взаи́мен (bg) (vzaímen)
Catalan: recíproc (ca), mutu
Chinese:
Mandarin: 相互 (zh) (xiānghù), 互相 (zh) (hùxiāng)
Czech: vzájemný (cs)
Danish: reciprok (da)
Esperanto: reciproka
Finnish: vastavuoroinen (fi)
French: réciproque (fr) m or f
Galician: recíproco m
Georgian: ორმხრივი (ormxrivi), თანაზიარი (tanaziari), ურთიერთზიარი (urtiertziari)
German: gegenseitig (de), reziprok (de)
Greek: αμοιβαίος (el) (amoivaíos)
Hebrew: הדדי‎ (he) (hadadi)
Hungarian: kölcsönös (hu)
Icelandic: ^{(please verify)} gagnvirkur
Latin: mūtuus. reciprocus
Lithuanian: savitarpinis
Macedonian: взаемен (vzaemen)
Maori: whakautuutu
Norwegian:
Bokmål: gjensidig (no)

Nynorsk: gjensidig
Polish: obopólny (pl), obustronny (pl), wzajemny (pl)
Portuguese: recíproco (pt)
Romanian: reciproc (ro), reciprocă f
Russian: взаи́мный (ru) (vzaímnyj), обою́дный (ru) (obojúdnyj)
Serbo-Croatian:
Cyrillic: узајаман

Roman: uzajaman (sh)
Slovak: vzájomný
Slovene: vzajemen
Spanish: mutuo (es), recíproco (es)
Turkish: çift taraflı, karşılıklı (tr)
Ukrainian: взає́мний (vzajémnyj)
Volapük: rezipik (vo)

done, given, felt, or owed in return

reciprocal (plural reciprocals)

(arithmetic) The number obtained by dividing 1 by another given number; the result of exchanging the numerator and the denominator of a fraction.
0.5 is the reciprocal of 2.
(grammar) A construction expressing mutual action.
- 2008, Ekkehard König, Volker Gast, Reciprocals and Reflexives: Theoretical and Typological Explorations
  Depending on where reciprocalization applies (syntax vs. lexicon), the relevant reciprocal verbs are claimed to exhibit specific properties, in particular: (i) syntactic reciprocals are fully productive whereas lexical reciprocals have only limited productivity; […]

in mathematics