crackers

cracker +‎ -ers. The South African sense derive their name from their sound and their status as a plurale tantum by association with "trousers". The adjectival sense derives from British naval expressions referring to firecrackers in one's head, originally as "he's got the crackers" and then "he's gone crackers" before the present "he is crackers".

crackers

1. plural of cracker
2. (South Africa, only plural) A kind of noisy leather pants or trousers.
   • 1849, E.E. Napier, Excursions in Southern Africa, volume II, page 13:

     Sheepskin trousers—which, from the sound they make at every movement of the wearer, are called ‘crackers’.

crackers (comparative more crackers, superlative most crackers)

1. (UK, colloquial) Crazy, insane.

   Synonyms: see Thesaurus:insane

   • 2021 May 5, Graeme Pickering, “Managing Metro's morphosis”, in RAIL, number 930, page 52:

     He acknowledges that it must seem "a crackers thing to say", but given the substantial progress which has been made in other areas of the business, his optimism isn't without foundation.

   • 2022 July 30, Dominic Cummings, quotee, “‘Ambition greater than ability’: Liz Truss’s rise from teen Lib Dem to would-be PM”, in The Guardian‎:

     Dominic Cummings, Boris Johnson’s former chief adviser, told the online magazine UnHerd in May that Truss was “as close to properly crackers as anybody I have met in parliament” and would be an “even worse” prime minister than Johnson.

• recracks