What is the meaning of the title "The Naked Gun" in the series of detective-spoof movies starring Leslie Nielsen? Is it a joke based on an existing detective movie with a similar name? Or perhaps a play on a phrase like "the naked eye"?
The Naked Gun is a fabricated title designed to evoke the old police thrillers of yesteryear.
The film is an offshoot of a short-running TV series, Police Squad! (1982), which starred Leslie Nielsen in the same role and which itself is a pastiche on an older series from the 50s called M Squad (1957) - even going so far as to emulate the theme tune and keep the main character's christian name.
The title might also be an homage to Naked City (1958-1963), another TV show from the 50s and 60s that dealt with the day to day lives of homicide detectives in New York's 65th Precinct.
In addition to the other answers - and maybe a bit too obvious - the movie is very prone to slapstick and sometimes sexualized humor. To have the word "naked" in a movie title, might already raise some brows. While accompanied with the word "gun", a phallic device known for its willingness to propel emissaries out of it, it is a quite graphic description of a naked member.
A title like that evokes more connotations of another genre than the detective one.
It is comparable with the Austin Powers sequence where characters are completing each others sentences about Guns, Wieners, Members and such.