macroinitiator

https://doi.org/10.1351/goldbook.08963
Macromolecule containing initiator functionality.
Note:
The dormant species in RDRP such as ATRP or SRMP is often referred to as a macroinitiator.
Source:
PAC, 2022, 94, 1093. 'Terminology for chain polymerization (IUPAC Recommendations 2021)' on page 1123 (https://doi.org/10.1515/pac-2020-1211)