USA, 1923: a court in which a perpetrator of a minor offence may sentence themself and their fellow offenders—USA, 1925: a court in which a perpetrator of a minor offence may pay a fixed fine without having to stand trial
something or someone that is unalloyed, throughgoing, trustworthy—USA, 1848—refers to gold with the complete purity of twenty-four parts out of twenty-four
as ‘coats for goalposts’: UK, late 19th century—refers to the type of informal football played by young people in public spaces, in which coats or/and jumpers belonging to the players are used as improvised goalposts
Canada, 1977: pouch-pack milk, as opposed to cartoned milk—UK, 1984: bag-in-box wine (said to be of Australian-English origin, but this is not corroborated)
to create a diversion, in order to avoid a dangerous or unpleasant situation—UK, 1730—alludes to the Preface to A Tale of a Tub (1704), by Jonathan Swift
Australia, 1940 (?)—UK, 1963—origin unknown—either somehow derived from the sense ‘to be parched’ of the phrase ‘to spit feathers’ or a distinct phrase which happens to be identical in form