IPA: /ˌæn.ti.səbˈvɜː.sɪv/
KK: /ˌæn.ti.səbˈvɜːr.sɪv/
Opposing or acting against efforts to undermine or overthrow a government or authority.
The government implemented antisubversive measures to protect national security.
Antisubversive → It is formed from "anti-" (meaning against) and "subvertere" (from Latin, meaning to overturn or undermine) and "-ive" (meaning having the nature of). The word "antisubversive" describes something that has the nature of being against the act of undermining or overturning established systems or authorities.
Think of being 'against' ('anti-') something that 'overturns' ('subvertere') — that's why antisubversive means opposing efforts to undermine.