IPA: //ˈfæn.sɪ.fəl.nəs//
KK: /ˈfæn.sɪ.fəl.nəs/
The quality of having imaginative or unrealistic ideas.
Her fancifulness often led her to create wonderful stories that captivated her friends.
Fancifulness → It is formed from "fanciful" (from Middle English *fanciful*, meaning imaginative or whimsical) and "-ness" (meaning the state or quality of). The word "fancifulness" refers to the quality of being imaginative or whimsical.
Think of someone who is very imaginative and has a lot of ideas — that's what 'fancifulness' means, the quality of being full of fancy or imagination.