For places like "St Louis", "Mt Pleasant", and "Ft Myers", what type of words are "St", "Mt", and "Ft"? [closed]

I've noticed, while working on code to handle addresses, that many parts of street names have common abbreviations, such as "St" for "Saint", "Mt" for "Mount" and so forth.

Is there a specific name for these types of words, (in the context of place names)?

I am also interested both in any information on when this practice originated and why it is used.

Solution 1:

These are abbreviations. Specifically, abbreviations of parts of names.

As such, they aren't really the correct name, but it may be written as such including on official signage, shop signage, company letterheads and invoices, postal addresses on envelopes, or entered into web forms.

Traditionally, where proper names consist of multiple words, and some parts are very common, that part may be abbreviated. The only consideration seems to be whether it will cause confusion.

This is even done with proper names of people. For example, "Charles" may be abbreviated to "Chas", "George" to "Geo" and "William" to "Wm" in signage. These are very common English given names, and the abbreviations are also commonly known, so no confusion is caused.

Examples:

• William Allan and Son, Butchers: http://allanthebutchers.co.uk/index.html
• George Middlemiss: https://www.cephas.com/Details.aspx?Ref=1147833&searchtype=&contributor=0&licenses=1,2&sort=DATE&cdonly=False&mronly=False
• Charles West, Stationery: https://ipswich-lettering.co.uk/brunswickrdpo.html

I'm told that this was even done in Parish records of births, marriages and deaths (though not in registry office records).

Note that even if a person is not familiar with the abbreviation, he can use the fact that we only abbreviate common names (or parts thereof) to deduce the correct name. And indeed in most cases it doesn't really matter, the letter will still get there.

Note that some names abbreviate to the same sequence of characters, the main example is "Street" vs "Saint", both abbreviate as "St". This is not generally ambiguous because "Saint" is generally one of the first words, and "Street" is generally the last. So "St. Joseph St." is "Saint Joseph Street".

As always the purpose is communication; if no human is confused there is no problem. (Machines work for us, not vice versa).

What if the abbreviation is the official name?

It may be that for some places, the abbreviation is the "official" name. In this case the other of the pair would be called the "expansion". Commenter @davos gives the example of "St Augustine, Florida". So if a programmer was writing code to correct addresses, he should consider "Saint Augustine" equivalent, and correct it to the official name.