IPA: /ɪmˈpɛtʃuəsnəs/
KK: /ɪmˈpɛtʃuəsnəs/
The quality of acting quickly and without thinking carefully, often leading to hasty decisions.
Her impetuousness often got her into trouble because she didn't consider the consequences of her actions.
Impetuousness is formed from "impetuous" (from Latin "impetuosus", meaning violent or hasty) and the suffix "-ness" (meaning the state or quality of). The word describes the state of being characterized by sudden or rash actions, often without careful thought.
Think of someone acting in a 'violent' or 'hasty' manner ('impetuous') — the '-ness' indicates the quality of that behavior.