IPA: /ˌæn.tiˈtɛr.ə.rɪ.zəm/
KK: /ˌæntiˈtɛrəˌrɪzəm/
Actions or policies designed to prevent or combat acts of terrorism.
The government has implemented new antiterrorism measures to enhance national security.
Antiterrorism is formed from "anti-" (meaning against) and "terrorism" (from Latin "terror" meaning fear and the suffix "-ism" indicating a practice or ideology). The word refers to actions or policies that are against the practice of terrorism, aiming to combat and prevent acts of terror.
Think of 'anti-' meaning against, and 'terrorism' relating to fear and violent acts. This helps you remember that antiterrorism means actions taken against acts of terror.