radicalism

US /ˈræd.ɪ.kəl.ɪ.zəm/
UK /ˈræd.ɪ.kəl.ɪ.zəm/
1.

chủ nghĩa cấp tiến

the belief that there should be great or extreme social or political change:

:
Evidence of his youthful radicalism remained buried in his poems of the period.