IPA: /ˈfɪtfəli/
KK: /ˈfɪtfəli/
In a way that is not steady or regular, often occurring in bursts or fits.
She slept fitfully, waking up several times during the night.
Fitfully → It is formed from "fit" (from Old English *fitt*, meaning a sudden attack or a short period of activity) and the suffix "-fully" (meaning in a manner full of). The word "fitfully" describes something that occurs in bursts or intermittently, full of fits.
Think of something happening in sudden bursts or attacks, as suggested by 'fit' — that's why fitfully means occurring in a sporadic manner.