IPA: /ˈfrɪv.ə.ləs.nəs/
KK: /ˈfrɪvələsnəs/
The state or quality of being silly or lacking in seriousness; often refers to actions or things that are not important or meaningful.
Her frivolousness was evident in her choice of entertainment, as she preferred light comedies over serious dramas.
Frivolousness → It is formed from "frivolus" (from Latin, meaning worthless or trivial) and the suffix "-ness" (meaning the state or quality of). The word "frivolousness" refers to the quality of being trivial or lacking in seriousness.
Think of 'worthless' ('frivolus') to remember that 'frivolousness' means the state of being trivial or not serious.