ratty /ˈɹæti/adjective 5noun 1forms 2 adjective5 •Resembling or characteristic of a rat; ratlike. •(informal, figurative) In poor condition or repair.The Marcher lord was still clad in his ratty black cloak and dented breastplate with its chipped enamel lightning. — 2000 •(informal, figurative) Annoyed, bad-tempered, irritable.He got bad, he got ratty, he would take it out on people around him. He was mean when it turned against him. — 2009 •(informal, figurative) Crazy, mad; ridiculous; slightly strange, eccentric; also (followed by about, on, or over), attracted to, infatuated with. •Infested with rats. noun1 •Synonym of knock down ginger (“prank of knocking on a front door and running away”). formsrattier · rattiest