Characteristic of a brat; childishly rude and annoying.(adjective)
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Use "brattish" in a sentence
"He tells Young that he regrets his "spoilt and brattish" behaviour when he won a Bafta in 2008 for Gavin & Stacey."
"When Lleyton Hewitt burst on to the scene as a snarling, brattish teenager with his baseball cap on back to front, Wimbledon did not know quite what to make of him."
"The first episode told the story – of, as even a fule will know through cultural osmosis, the fallout from a family barbecue that ends with a brattish three-year-old, whose parents refuse to discipline him, being slapped by someone else – from the host Hector's point of view."