mesolytic cleavage

https://doi.org/10.1351/goldbook.M03843
Cleavage of a bond in a radical ion whereby a radical and an ion are formed. The term reflects the mechanistic duality of the process, which can be viewed as homolytic or heterolytic depending on how the electrons are attributed to the fragments.
Source:
PAC, 1994, 66, 1077. 'Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)' on page 1139 (https://doi.org/10.1351/pac199466051077)