1) Careless 2) Careless, thoughtless 3) Deaf 4) Foolhardy 5) Incautious 6) Indifferent 7) Not a bit cautious 8) Not a bit concerned 9) Regardless 10) Thoughtless 11) Unheeding 12) Unobservant 13) Without care 14) Without consideration 1) Careless 2) Deaf 3) Inadvertent 4) Incautious 5) Inconsiderate 6) Rash 7) Regardless 8) Unheeding 9) Unmindful 10) Unreflective 11) Unthinking 12) Unwary 
• (a.) Without heed or care; inattentive; careless; thoughtless; unobservant.
Heed'less adjective Without heed or care; inattentive; careless; thoughtless; unobservant. « O, negligent and heedless discipline!» Shak. « The heedless lover does not know Whose eyes they are that wound him so.» Waller. -- 
[adj] - marked by or paying little heed or attention 2. [adj] - characterized by careless unconcerned
reckless adjective characterized by careless unconcern; `the heedless generosity and the spasmodic extravagance of persons used to large fortunes`- Edith Wharton; `reckless squandering of public funds`