A chemical reaction between two compounds in which parts of each are interchanged to form two new compounds (AB+CD=AD+CB) WordNet 3.0 & Open English WordNet

A salt metathesis reaction, sometimes called a double displacement reaction, is a chemical process involving the exchange of bonds between two reacting chemical species which results in the creation of products with similar or identical bonding affiliations. Wikipedia

Exchange of bonds between two reacting chemical species Wikipedia Disambiguation

Chemical reaction involving exchange of ionic bonds between four species Wikidata

A reaction between two substances in which two parts of each substance are exchanged; metathesis. Wiktionary

The double decomposition of inorganic salts. Wiktionary