IPA: /ɑːrˈkeɪɪkli/
KK: /ɑrˈkeɪɪkli/
In a way that is old-fashioned or no longer in common use.
The text was written archaically, making it difficult for modern readers to understand.
Archaically → It is formed from "archaic" (from Greek "archaios", meaning ancient or old) and the suffix "-ly" (meaning in a manner of). The word "archaically" means in a manner that is characteristic of an earlier or ancient time.
Think of something being done in an 'ancient' way ('archaic') — the '-ly' shows how it is done, so 'archaically' means in an ancient manner.