IPA: /ʌnˈpʌblɪʃəbl/
KK: /ʌnˈpʌblɪʃəbl/
Not suitable for being published or made public.
The author's latest work was deemed unpublishable by the editors.
Unpublishable → It is formed from "un-" (meaning not) and "publish" (from Latin "publicare", meaning to make public) and "-able" (meaning capable of). The word "unpublishable" means not capable of being made public or not suitable for publication.
Think of 'not' ('un-') being added to 'make public' ('publicare') and 'capable of' ('-able') — that's why unpublishable means something that cannot be made public.