B1
not giving enough attention to what you are doing
Dictionary examples:
The careless student wrote 'I love you' instead of 'Thank you' to his teacher. (0.0)
His careless spelling turned 'Dear Sir' into 'Dead Sir' in the important email. (0.0)
His careless texting led him to ask his boss out on a date. (0.0)
He made a careless remark about her appearance that really upset her. (42.8)
careless driving/drivers (51.3)
My son's teacher says that his work is often careless and sloppy. (86.0)