IPA: /ˌæntiˈrædɪkəlɪzəm/
KK: /æntiˈrædɪkəlɪzəm/
A belief or movement that opposes extreme political or social ideas and actions.
The rise of antiradicalism has led to more moderate political discussions.
Antiradicalism is formed from "anti-" (meaning against) and "radicalis" (from Latin, meaning relating to the root or fundamental). The term refers to a stance or ideology that opposes radical changes or movements.
Think of being 'against' ('anti-') fundamental changes or ideas — that's what antiradicalism means.