rash or impulsive
impetuous - hasty
If you are ‘impetuous’, then you are likely to take action quickly and suddenly without proper planning or consideration of the consequences. While acting too hastily or carelessly can often lead to a negative outcome, this word does still have some positive connotations, occasionally denoting a sense of passion and fearlessness.
Claire’s sudden resignation from the company was an impetuous decision that she may well come to regret in the future.
James is young, carefree, and tackles problems with a sense of zeal and urgency. I quite admire his impetuousness.
I was so enamoured by the house the real estate agent showed me that I offered to buy it on the spot. In hindsight, I really wish I hadn’t acted so impetuously!