The term hack, which entered general usage with a new, nontechnological sense of “solution” or “work-around,” as in the phrase “life hack,” in the previous decade has undergone an impressive divergence in meanings since it entered the English lexicon hundreds of years ago. However, as with the synonym kludge (also spelled kluge), the etymological origin of the word is disputed.
One school of thought is that hack simply derives from an Old High German word that refers to chopping. (A short, sharp cough is also called a hack.) From that meaning, it derived the figurative sense of crudely or ruthlessly working on something and then of simply toiling; by extension, the word was applied to being able or unable to manage or tolerate something: The now-rare expression “You just can’t hack it” expressed this idea.
In the era of modern technology, two new senses arose: One who writes computer programs as a hobby is a hacker and produces hacks, but the label also came to apply to one who illegally accesses a computer system. Hack also came to mean “creative solution to a computer problem,” so that, depending on context, a hacker may be benign or malicious.
But the technological sense is also said to have derived ultimately from the unrelated word hackney. The term stems from the place name Hackney, which now refers to a borough of London but in medieval times identified a marshy area; the etymology of the name is likely “Haca’s (or Haka’s) island,” referring to an area of solid ground surrounded by marshlands that was associated with a person by that name.
Hundreds of years later, when the area had become drier, it was used as pastureland, and the name was employed to refer to horses used for hire and, specifically, to pull carriages. Later, a particular type of carriage, by association, came to be called a hackney. This type was often used for hire, which explains why hackney, and the shortened version hack, were preserved to refer to motorized taxicabs and, by extension, cab drivers.
The extension proliferated to denote people who, like the horses, performed routine or mercenary work; this included prostitutes and then writers for hire, who were considered to also be selling themselves (rather than writing as an artistic endeavor). “Hackney writer” preceded “hack writer” and simply hack to denote a mediocre or mercenary wordsmith. Hack also pertains, in the phrase “party hack,” to a low-ranking functionary in a political organization. (The idea of the hackney horse’s indiscriminate use led to the use of the term hackneyed to mean “trite”; the word was applied, coincident with the sense of “writer for hire,” to clichéd writing.)
Some people believe this evolution of hack, rather than the synonym for “chop,” to be the source of the technological sense.
Meanwhile, the equestrian path is continuous: Hackney denotes a breed of horse suitable for ordinary riding (and a related pony breed). Hacking is an activity in eastern North America equivalent to the pastime of trail riding in the western regions of the continent, and hack shows are equestrian competitions in which the horse’s manners, movement, and physical form are evaluated.