crackers

Etymology
. 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".

Noun

 * 1)  A kind of noisy leather pants or trousers.
 * 1)  A kind of noisy leather pants or trousers.

Adjective

 * 1)  Crazy, insane.