reck·less 
(rĕklĭs)
(rĕklĭs)adj.
Acting or done with a lack of care or caution; careless or irresponsible.
[Middle English reckeles, probably alteration (influenced by recken, to reck) of recheles, retcheles, from Old English rēcelēas; see reg- in the Appendix of Indo-European roots.]
reckless·ly adv.
reckless·ness n.
Synonyms: reckless, rash1, foolhardy, temerarious
These adjectives mean given to or marked by unthinking boldness. Reckless suggests wild carelessness and disregard for consequences: "conceiving measures to protect the fur-bearing animals from reckless slaughter" (Gertrude Atherton).
Rash implies haste, impetuousness, and insufficient consideration: "Take calculated risks. That is quite different from being rash" (George S. Patton).
Foolhardy implies injudicious or imprudent boldness: a foolhardy attempt to wrest the gun from the mugger. Temerarious suggests reckless presumption: "this temerarious foeman who dared intervene between himself [the elephant] and his intended victim" (Edgar Rice Burroughs).
These adjectives mean given to or marked by unthinking boldness. Reckless suggests wild carelessness and disregard for consequences: "conceiving measures to protect the fur-bearing animals from reckless slaughter" (Gertrude Atherton).
Rash implies haste, impetuousness, and insufficient consideration: "Take calculated risks. That is quite different from being rash" (George S. Patton).
Foolhardy implies injudicious or imprudent boldness: a foolhardy attempt to wrest the gun from the mugger. Temerarious suggests reckless presumption: "this temerarious foeman who dared intervene between himself [the elephant] and his intended victim" (Edgar Rice Burroughs).