parallel effect 

https://doi.org/10.1351/goldbook.08194
Change of the position of the transition state upon stabilization or destabilization of a structure (or structures) along the assumed minimum-energy reaction path.
Source:
PAC, 2022, 94, 353. (Glossary of terms used in physical organic chemistry (IUPAC Recommendations 2021)) on page 478 [Terms] [Paper]