From Longman Dictionary of Contemporary Englishcarelesscare‧less /ˈkeələs $ ˈker-/ ●●○ adjective 1 CARELESSnot paying enough attention to what you are doing, so that you make mistakes, damage things etc OPP careful It was careless of him to leave the door unlocked. a careless mistake careless drivingcareless with He’s careless with his glasses and has lost three pairs. Careless talk can be disastrous for a business.2 PLAN[usually before noun] natural and not done with any deliberate effort or attention He ran a hand through his hair with a careless gesture.3 IGNOREnot concerned about somethingcareless of a man careless of his own safety She gave a careless shrug. ► Do not use ‘careless’ to mean that someone has no worries. Use carefree: They all felt happy and carefree. —carelessly adverb —carelessness noun [uncountable]THESAURUScareless not paying enough attention to what you are doing, so that you make mistakes, damage things etcI made a few careless mistakes.It was careless of you to leave your purse lying about.He started getting careless about taking his medication.clumsy often dropping or breaking things because you move around in a careless wayI’m so clumsy, I spilt milk all over the floor.a clumsy childsloppy careless and lazy in the way you do your work or in your behaviour generallyAs a student, he was brilliant but sloppy.I will not tolerate sloppy work.reckless especially written doing dangerous or stupid things without thinking about your own or other people’s safetyThe driver of the car was arrested for reckless driving.His actions showed a reckless disregard for human life.irresponsible careless in a way that might affect other people, especially when you should be taking care of themIt’s irresponsible for parents to let their children smoke.his irresponsible attitude to keeping animalstactless carelessly saying something that upsets or embarrasses someone, without intending to do thisHe kept making tactless remarks about her appearance. a tactless questionI thought it would be tactless to ask about her divorce.casual not being careful enough about something and treating it as though it is not importantHe seems to have a very casual attitude towards his work.She disliked the casual way in which he made decisions affecting other people’s lives. negligent careless about something that you are responsible for, so that serious mistakes are made – used especially when someone will be officially punished for thisThe doctor was negligent in using the wrong type of needle.They found him guilty of negligent conduct.
Examples from the Corpuscareless• People just thought I was being careless.• Don't be so careless.• After a few weeks, he started getting careless about taking his medication.• Keaton got careless and left fingerprints at the scene of the crime.• Pryce accused the other driver of being careless and negligent.• Officials suspect that the fire was started by careless campers.• He was fined 300-pounds and given six penalty points for careless driving.• Careless handling of pesticides causes dozens of accidents on farms every year.• Some careless idiot forgot to lock the door and the dog got out.• Katz argued that the police used too much force and were careless in making arrests.• I made a few careless mistakes.• Every year, some careless motorists wind up blinded by acid.• Huy grabbed one of the torches and brought it closer, careless of the wax dripping on to the dead skin.• It was very careless of you to leave your purse lying on the desk.• Witnesses say the argument started after a careless remark about the victim's wife.• She snapped out careless retorts and soared in brief Puccinian reminiscences with equal ease.• It was a delightful, careless room, untidy and rather deficient in comfortable chairs.• I was too careless to really focus.• The building had been finished in a very careless way, with loose wires and unpainted ceilings.• Terence has always been careless with his money.• You say a few careless words to a neighbour and suddenly everyone knows about it.• Investigators are still not sure whether the damage was intentional or due to careless work.