IPA: /ˌæn.ti.hɪsˈtɒr.ɪ.kəl/
KK: /æntiˈhɪstərɪkəl/
Describing something that goes against or contradicts historical facts or events.
The author's antihistorical perspective challenged the traditional narratives of the past.
Antihistorical is formed from "anti-" (meaning against) and "historical" (from Greek "historikos", meaning relating to history). The word describes something that is against or contrary to historical facts or narratives.
Think of 'anti-' meaning against, and 'historical' relating to history — this helps you remember that antihistorical refers to something that goes against historical facts.