careless

The word “careless” means not paying enough attention, so that mistakes or accidents happen. In plain terms, not taking enough care, so things get done sloppily or dangerously.

“Careless” is pronounced KEH-uh-lihs (/kɛɹ.ləs/ in IPA).

Here is “careless” used in a sentence: “A careless mistake cost them the contract.”

Words with a similar meaning to “careless” include cursory, derelict, heedless, irregardless, irrespective and lash.

The opposite of “careless” — its antonyms — is meticulous.

“Careless” is an adjective.

The word “careless” comes from Old English. From Old English carlēas, from care + -less ("without").

“Careless” is an uncommon word in modern English, usually learned at around the B1 level.

Careless describes a lack of attention that leads to mistakes or accidents, often without any awareness of the risk involved, while reckless implies a person knew there was danger but disregarded it anyway. Reckless behavior generally carries a stronger sense of deliberate risk-taking than careless behavior.

Careless is the everyday word for not paying enough attention, while negligent is often used in legal and professional contexts to describe a failure to exercise a required standard of care, sometimes with legal consequences. A careless mistake might just be embarrassing, whereas negligent conduct can lead to liability.

Careless and carefree look similar but mean very different things: careless means inattentive in a way that causes errors, while carefree means free from worry or responsibility in a positive, relaxed sense. A carefree afternoon is pleasant, but a careless mistake is a problem.