reckless
1. [ adjective ] marked by unthinking boldness; with defiant disregard for danger or consequences
Synonyms: foolhardy rash
Examples:

"foolhardy enough to try to seize the gun from the hijacker" "became the fiercest and most reckless of partisans"-Macaulay "a reckless driver"

Related terms: bold
2. [ adjective ] characterized by careless unconcerned
Synonyms: heedless
Examples:

"the heedless generosity and the spasmodic extravagance of persons used to large fortunes"- Edith Wharton "reckless squandering of public funds"

Related terms: careless
Similar spelling:   recklessly
  recoilless
  Rickles