cock up

Origin: The first citation in the Oxford English Dictionary is from the Dictionary of Forces’ Slang (1948). The OED suggests that it derives ultimately from the noun cock, but gives no further detail. The nature of the earliest citation suggests that this expression entered the wider language from military slang, making etymologies from typesetting or archery (see below) seem unlikely. The term is sometimes attributed to the days of manual typesetting, when a letter that had become wedged slightly higher than the other letters on the line was said to be “cocked up”. Another claim relates to medieva. Origin information sourced from Wiktionary contributors (CC BY-SA 4.0).