A G-string is a type of thong, a narrow piece of cloth, leather, or plastic, that covers or holds the genitals, passes between the buttocks, and is attached to a band around the hips. A G-string is most commonly worn by women as underwear, but may also be worn by men. It may also be worn in swimwear, where it may serve as a bikini bottom, but may be worn alone as a monokini or topless swimsuit. G-strings may also be worn by exotic or go-go dancers. As underwear, a G-string may be worn in preference to panties to avoid creation of a visible panty line.
Since the 19th century, the term geestring referred to the string which held the loincloth of Native Americans and later referred to the narrow loincloth itself. William Safire in his Ode on a G-String quoted the usage of the word "G-string" for loincloth by Harper's Magazine 15 years after John Hanson Beadle's 1877 usage and suggested that the magazine confused the word with the musical term G-string (i.e., the string for the G note). This is apocryphal, as the narrowest string on a violin is the E string.
Safire also mentions the opinion of linguist Robert Hendrickson that G (or gee) stands for groin, which was a taboo word at the time.
The G-string first appeared in costumes worn by showgirls in Earl Carroll's productions during the Jazz Age. Linguist Robert Hendrickson believes that the 'G' stands for 'groin'. The Oxford English Dictionary reports that the G-string was originally a narrow strip of fabric worn by Indian women. During the Depression, a "G-string" was known as "the gadget", a double-entendre that referred to a handyman's "contrivance", an all-purpose word for the thing that might "fix" things. During the 1930s, the "Chicago G-string" gained prominence when worn by performers like Margie Hart. The Chicago area was the home of some of the largest manufacturers of G-strings and it also became the center of the burlesque shows in the United States.
^Adams, Cecil (2010-09-02). "What does the G in G-string stand for?". The Straight Dope. Retrieved 2014-12-21. Littell's Living Age, Vol. IX, 1846: 'Their arms were a small hatchet, stuck in their girdle-string.' While that hardly proves G-string is an abbreviation of girdlestring, the fact that the latter word existed and means the same as G-string supports my conjecture that the shorter term derived from the longer.