careful
adjective
ˈkeəfl 
ˈkerfl 
1 [not before noun] giving attention or thought to what you are doing so that you avoid hurting yourself, damaging something or doing something wrongBe careful!careful to do something He was careful to keep out of sight.careful not to do something Be careful not to wake the baby.careful when/what/how, etc. You must be careful when handling chemicals.Be careful what you say.careful of/about/with something Be careful of the traffic.Please be careful with my glasses (= Don't break them).I'm very careful about washing my hands before eating (= I make sure I do it).careful (that)… Be careful you don't bump your head.2 giving a lot of attention to detailsa careful piece of worka careful examination of the factsAfter careful consideration we have decided to offer you the job.Opposite
carelesscarefully ˈkeəfəli ˈkerfəli Opposite
carelesslycarefulness ˈkeəfəlnəs ˈkerfəlnəs Idioms
you can't be too careful
used to warn somebody that they should take care to avoid danger or problems
Don't stay out in the sun for too long—you can't be too careful.careful with money
not spending money on unimportant things
His mother had always been careful with money.