I agree with Sir Brian.
Yeah, the terminology is all pretty interchangeable. In the Liechtenauer system, what we call a feint is often referred to as a "failer" (just meaning that it fails to do what the opponent is expecting). A true "failer" is an attack that can still carry through and do what it looks like it's doing if the opponent doesn't react to it, but your intention is to draw that response and then change line of attack. It has to be a real attack so that it's believable, and can still land if they don't react properly.
Dropping the shoulder isn't really a "failer" in that regard, since you're intentionally giving a "tell" to misdirect him without having made the attack yet, but the word "fake" or "feint" probably still work here.
I like the idea of using the word "fake" for an intentional "tell", and use the word "feint" for a false attack, and "failer" for a true attack that is meant to draw out a response and can change lines quickly. But in the end, it's all a fine line between them, and it's all misdirection, so it may not matter much what we call it.