“The full Monty” is a British slang term which means “the whole thing.” Americans associate the term specifically with nudity, thanks to a 1997 British comedy film, The Full Monty, in which nudity is a major plot device. As with many colorful slang terms, the origins of “the full Monty” are a bit difficult to unravel, and most slang dictionaries simply note “origins unknown,” because none of the explanations for the term can be verified.
Evidence suggests that Britons have been using “the full Monty” since at least the 1950s, although the term did not appear in print until the 1980s. By the 1980s, the slang term was well-known enough that when it appeared in print, writers assumed that readers knew what it meant. Americans were unfamiliar with the term until 1997, after which it entered the American lexicon to describe a state of nudity.
One of the most likely explanations for the origins of this term lies in a tailor named Sir Montague Burton, who opened his business in 1904. “Monty,” as he was known, prided himself on offering complete tailored suits, and it is conceivable that customers referred to such suits as “the full Monty,” and that the term slowly spread into the rest of society. Sir Burton was certainly a very well-known and respected tailor, making this explanation plausible, if impossible to prove.
It has also been suggested that “the full Monty” may be a corruption of “the full amount,” or a reference to the pool of bets in a card game called Monte. Since Monte was historically played mostly in Spain, the jump to the British Isles is left to the imagination. Another gambling-related explanation suggests that the term is a reference to the famous casino at Monte Carlo.
Other explanations focus on another famous Monty from British history, Field Marshal Montgomery. Allegedly, the Field Marshal was fond of wearing all of his medals at all times, sporting a complete set which could have been known in military slang as “the full Monty.” Field Marshal Montgomery supposedly was also a strong promoter of the full British breakfast, even in times of strain, so it is conceivable that the soldiers in his command grew accustomed to seeing the Full Monty on the breakfast table. Alas, charming as these explanations are, both are apocryphal, although Field Marshal Montgomery certainly had the nickname “Monty.”