Is "fillet" a different word in "salmon fillet" than in "leather fillet"

In the question "Is there a name for words which are pronounced differently depending on which definition is being used?" it was suggested by two people that when the word "fillet" is used to describe a thin strip of leather, it is a different word than when "fillet" is used to describe a thin strip of salmon, because the pronunciation differs.

The culinary pronunciation is "fil-AY," while the engineering pronunciation is "FILL-it."

This seems VERY strange to me. Especially because the pronunciation apparently doesn't differ in British English, even though it does in American English.

Are the phrases "salmon fillet" and "leather fillet" using two different words to describe a thin strip of material, even though they mean the same thing, and have the same etymology? It seems weird to think of a word essentially being a synonym to itself.

Also, if those two versions of "fillet" are different words, then are they the same word when they are being used by a British speaker?

This all seems very confusing.

Addendum:

In response to an email I sent to the editors of the online Mirriam-Webster Dictionary, I received the following reply (in part)

In the case of "fillet", I would argue that those are actually two different words. They may have the same etymology, but in current English they are homographs and heteronyms.


Joshua S. Guenter, Ph.D. Editor of Pronunciation

Although it initially seemed strange to me, I think I'm getting my head around how the "thin strip of material" definition of fillet is in the process of, or has finished, evolving from one word into two different words.

Thank you to all of you.


As a mechanical engineer, the word "fillet" is always pronounced "Fill-it" when talking about machining and modeling purposes (at least in the US). In this sense, it is not a "strip of material" rather it is the act of machining off a sharp external corner (chamfers are also common, whereas fillets are rounded corners, chamfers are a flat cut). Fillets also describe the material left in an internal corner usually cause by pockets cut by ball end mills (the profile is circular, so cutting a sharp internal edge is generally a difficult and expensive procedure).

The terms fillets and rounds are often synonymous, but sometimes one will be used to to refer to internal corners and the other for external corners.

How this came to be, I don't know. Maybe its because creating a 'fillit" on an external corner is like cutting off a small, precise bit of material, similar to "fillay-ing" a fish. Then just take old engineering men who don't want to sound pretentious and it becomes "fillit".

It could also be because fillets in internal corners "fill" the corner with material. Fillet welds are also extremely common and this would add material opposed to how a machining operation would really be leaving material.

Either way, the pronunciation of this word is a very common lesson old engineers dole out to newbies right out of school. Those old guys love it.


Use "filet" when you are trying to use the French word for "fillet". "Filet mignon" is a French phrase and hence "filet" is pronounced "fill-ay". Fillet of salmon or salmon fillet is an English phrase and here the word in question is pronounced "fill-itt". I have no idea about the etymology.

In my British English experience, I have only ever heard the word "filet" in reference to French-named dishes, but here in the US, I have certainly heard the word "fillet" pronounced as "fill-ay" to the point that I was once reprimanded by a waiter who told me I must pronounce "fillet" as "fill-ay". Pretty sure I didn't tip much that night.