Definition of Old Testamentism in English:

Old Testamentism

Pronunciation /ˌəʊl(d) ˈtɛstəm(ə)ntɪz(ə)m/

noun

rare
  • The religious doctrine of the Old Testament; excessive or inappropriate adherence to such doctrine.

Origin

Early 20th century; earliest use found in The Spectator. From Old Testament + -ism.