IPA: /ˌæn.tiˈmɪl.ɪ.tɛr.i/
KK: /ˌæntiˈmɪlɪˌtɛri/
Opposed to the armed forces or military actions.
The group held an antimilitary protest to express their views against war.
Antimilitary is formed from "anti-" (meaning against) and "military" (from Latin "militari", meaning pertaining to soldiers or warfare). The word describes a stance or attitude that is against military forces or military action.
Think of 'anti-' meaning against, and 'military' relating to soldiers — this helps you remember that antimilitary refers to being against military forces.