The term half-cockis as old as flintlock guns and appears in print from about the mid18th century; "The gun being at Half-Cock, the Spring acts upon theTumbler with more Advan
…tage." The earliest knownuse of the phrase 'going off at half-cock' comes from London andIts described, in 1761 as "Some arms taken at Bath in the year1715, distinguished from all others in the Tower, by having what iscalled dog locks; that is, a kind of lock with a catch to preventtheir going off at half-cock." We now commonly use'go off at half-cock' or, in America, 'go off half-cocked', to mean'speak or act impulsively and without the right preparation'. Andtherefore this clearly alludes to the sudden discharge of afirearm. Despite that, the first use of the phrase had a completelydifferent meaning. When the 'half-cocked' was used it wassupposedly to mean tipsy, or half-drunk. (MORE)