preformist
/ˈpriːfɔːrˌmɪst/ or /ˈpriːfɔːrmɪst/Definitions
1. noun
A preformationist, one who believed that the fetus was preformed in the egg or sperm
“The scientist was a preformist in her views on embryonic development.”
2. noun
A person who believes that a pre-formed or pre-existent being or entity is at the root of the universe
“The philosopher was a preformist, arguing for a pre-existent divine being.”