IPA: /ˌpriːˈpʌb.lɪˌkeɪ.ʃən/
KK: /priːˌpʌb.lɪˈkeɪ.ʃən/
Relating to the period just before something is published, especially a book.
The marketing team prepared for the prepublication phase of the new novel.
Prepublication → It is formed from "pre-" (meaning before) and "publication" (from Latin "publicare", meaning to make public). The word refers to the stage or process that occurs before something is made public or published.
Think of something that happens 'before' ('pre-') it is 'made public' ('publicare') — that's what prepublication means.