If you are careful, you do something with a lot of attention.
If you are careless, you do things badly because you are not giving them enough attention. Careless is the opposite of careful.
Someone who is carefree has no worries and can therefore enjoy life.
| Adj. | 1. | careless - marked by lack of attention or consideration or forethought or thoroughness; not careful; "careless about her clothes"; "forgotten by some careless person"; "a careless housekeeper"; "careless proofreading"; "it was a careless mistake"; "hurt by a careless remark" inattentive - showing a lack of attention or care; "inattentive students"; "an inattentive babysitter" incautious - lacking in caution; "an incautious remark"; "incautious talk" unconcerned - lacking in interest or care or feeling; "the average American...is unconcerned that his or her plight is the result of a complex of personal and economic and governmental actions...beyond the normal citizen's comprehension and control"; "blithely unconcerned about his friend's plight" negligent - characterized by neglect and undue lack of concern; "negligent parents"; "negligent of detail"; "negligent in his correspondence" superficial - concerned with or comprehending only what is apparent or obvious; not deep or penetrating emotionally or intellectually; "superficial similarities"; "a superficial mind"; "his thinking was superficial and fuzzy"; "superficial knowledge"; "the superficial report didn't give the true picture"; "only superficial differences" imprudent - not prudent or wise; "very imprudent of her mother to encourage her in such silly romantic ideas"; "would be imprudent for a noneconomist to talk about the details of economic policy"- A.M.Schlesinger careful - exercising caution or showing care or attention; "they were careful when crossing the busy street"; "be careful to keep her shoes clean"; "did very careful research"; "careful art restorers"; "careful of the rights of others"; "careful about one's behavior" |
| 2. | careless - effortless and unstudied; "an impression of careless elegance"; "danced with careless grace" artless - simple and natural; without cunning or deceit; "an artless manner"; "artless elegance" | |
| 3. | careless - (usually followed by `of') without due thought or consideration; "careless of the consequences"; "crushing the blooms with regardless tread" |