reckless in WordNet English dictionary

1. marked by defiant disregard for danger or consequences
   "foolhardy enough to try to seize the gun from the hijacker"; "became the fiercest and most reckless of partisans"-Macaulay; "a reckless driver"; "a rash attempt to climb Mount Everest"
   foolhardy  heady  rash  reckless 
   
2. characterized by careless unconcern
   "the heedless generosity and the spasmodic extravagance of persons used to large fortunes"- Edith Wharton; "reckless squandering of public funds"
   heedless  reckless