ratty

Etymology 1

From rat + -y (suffix meaning ‘having the quality of’ forming adjective).

adj

1. Resembling or characteristic of a rat; ratlike.
2. Infested with rats.
3. (figurative, informal)
   1. 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, George R.R. Martin, A Storm of Swords, Bantam, published 2011, page 535
      I was having exactly that thought on a ratty mock-leather couch in Islington. 2006, Clive James, North Face of Soho, Picador, published 2007, page 80
   2. (Australia) Crazy, mad; ridiculous; slightly strange, eccentric; also (followed by about, on, or over), attracted to, infatuated with.
   3. (originally Britain) 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, Ian McDonald, River of Gods

Etymology 2

noun

1. Synonym of knock down ginger (“prank of knocking on a front door and running away”)