IPA: /ˈkoʊˌraɪtə/
KK: /ˈkoʊˌraɪtər/
A person who collaborates with others to write something, such as a book, article, or script.
She is a cowriter on the new novel that will be published next year.
Cowriter → It is formed from "co-" (meaning together) and "writer" (from Old English "writere", meaning one who writes). The word "cowriter" refers to a person who writes together with another person.
Think of two people writing "together" ('co-') — that's what a cowriter does.