The USPS has a list of street suffixes (like Street, Avenue, road, etc.) and acceptable abbreviations for them (like ST, AV, and RD)
One of them is Loaf (LF). I've done a bit of research and cannot find a definition of loaf that makes sense in the context of a street suffix.
We have the common definitions of the noun (bread) and verb (to lounge around), and a region-specific (UK) one where loaf=head/brain, ie, loaf of bread (rhymes with head) that I found on Wiktionary.
(https://en.wiktionary.org/wiki/loaf)
So what is a loaf in terms of a street name suffix?
Best Answer
Notice that the list of street suffixes you gave also includes words like "mountain", "valley", "stream", "glen", and other nature words.
According to Wikipedia, there are a few hills and mountains in the US called Sugar Loaf:
Here is a photo of a classic sugarloaf.
Apparently, the word sugarloaf is "now used chiefly in similes and metaphors to describe the shape of other objects" (here).
In fact, there is a conventional use of sugarloaf which refers only to specific landforms (see here).
All of this points to the fact that the abbreviation LF can plausibly be taken to stand for loaf in constructions abbreviating "Sugar Loaf", as in
That this is correct is corroborated by this website, where "LF" is used to abbreviate the "loaf" in "Sugar Loaf."
In fact, if you google "Sugar LF, address", you get a lot of hits for streets/places apparently called "Sugar Loaf."
One can (presumably) also use "LF" to abbreviate "loaf" in place names like "High Loaf" and "White Loaf", although I can find no addresses corroborating this.