"Signaling". I'm not actually sure exactly what "signaling" means—which is arguably reason enough for us not to use it. I get the impression that it's usually used to mean exactly the same thing as "indicating". If that's the case, we should stop using it (or else only use it when everyone knows exactly what we mean by), and just say "indicating" instead.
If these really are synonyms, then doesn't signaling win by having fewer syllables?
"Affect" (the noun). Wiktionary defines it as "a subjective feeling experienced in response to a thought or other stimulus; mood, emotion, especially as demonstrated in external physical signs". LW seems to use it as an exact synonym of "emotion".
Using it as a synonym of emotion would indeed be wrong, but I haven't noticed people using it that way. Got a concrete example? I also disagree with the definition you gave, though; it fails to capture what I see as the defining quality of affect that distinguishes it from emotions in general, which is that it has only one axis which runs from good to bad.
If these really are synonyms, then doesn't signaling win by having fewer syllables?
Whoops, I was unclear. When I said it seems like "it's usually used to mean exactly the same thing", I meant that some people on Less Wrong use it that way, not that that's the correct usage.
Using it as a synonym of emotion would indeed be wrong, but I haven't noticed people using it that way. Got a concrete example?
I suppose the only example that comes to mind is the term "affective death spiral", which doesn't seem (to me) to have anything in par...
Every so often, someone on Less Wrong uses a word wrong.
What does it mean to use a word wrong? Can't we use language however we want, as long as we manage to successfully communicate? Well, yes, we can, but we shouldn't. Jargon terms, in particular, are used by professionals in a certain field in order to communicate concepts that are applicable chiefly in that field. They often have very precise definitions—"incunable", for example, means "book printed in Europe before the year 1501", and "sweet crude oil" means "petroleum with a sulfur content less than 0.42%".
The thing about precisely-defined terms like these is that if you use one of them in a way that's at odds with its official definition, you can cause people to have more misunderstandings later on. I admit I can't think of a great example, but "obsessive–compulsive disorder" seems like a decent one: people often say "I'm so OCD" to mean that messy things annoy them, which seems like it could lead people to misunderstand when people actually have obsessive–compulsive disorder.
There are just two words I don't really like LW's usage of: