Definition of reactionism in English:
reactionism
noun
Reactionary principles or practice.
Pronunciation
reactionism
/rɪˈakʃ(ə)nɪz(ə)m/ /rɪˈakʃənɪz(ə)m/ Origin
Mid 19th century; earliest use found in Philip Schaff (1819–1893), theologian and historian. From reaction + -ism.