IPA: /ˌʌnɪnˈfɔːrmətɪvli/
KK: /ʌnɪnˈfɔrmətɪvli/
In a way that does not provide useful or helpful information.
The report was written uninformatively, leaving many questions unanswered.
Uninformatively → It is formed from "un-" (meaning not) and "inform" (from Latin "informare", meaning to shape or form an idea) and "-atively" (a suffix forming adverbs). The word means in a manner that does not provide information or is not informative.
Think of 'not' ('un-') providing a 'shape' or 'idea' ('inform') — that's why 'uninformatively' means not providing useful information.