From Longman Dictionary of Contemporary Englishbratbrat /bræt/ noun [countable] informal 1 BAD PERSONa badly behaved child a spoiled brat2 → army/navy/military etc brat —bratty adjective
Examples from the Corpus
brat• This is like an upper class brat.• And let some one else look after her little brats for a change.• Now go away, you nasty little brat.• The school is full of rich brats.• Should I tell him his kid is a spoiled brat?• Kids can be such brats and so mean.• But neither of these brats would kill him!• All his classmates were either married with brats or disgustingly overweight.spoiled brat• Stop acting like a spoiled brat.Origin brat (1500-1600) Perhaps from brat “rough or torn piece of clothing” ((10-20 centuries)), from Old Irish bratt “cloak”