IPA: /ˌæn.tiˈræd.ɪ.kəl/
KK: /æntiˈrædɪkəl/
Describing something that works against or opposes free radicals or radical ideas.
The antiradical treatment helped to reduce the damage caused by oxidative stress.
Antiradical is formed from "anti-" (meaning against) and "radical" (from Latin "radicalis", meaning relating to the root). The word describes something that is against radical ideas or movements.
Think of 'anti-' meaning against and 'radical' relating to the root of ideas — so antiradical means opposing fundamental changes.