[gmw]

Sometimes, yes, a word is just plain wrong. ... But your example, I think, would have to be judged in context. I can imagine some contexts in which a character might roar in terror (depending on the character and the circumstances), but it does seem unusual.

I remember being similarly knocked out of the story several times by the word choices and similes used in a YA series I read a while ago. For example the writer described an exceptionally clear window as being "perfectly translucent". I immediately stopped and thought "What?" Now it is true, one definition of translucent is clear or transparent, so technically/literally it works, but in my head translucence is associated with things that are specifically not perfectly transparent. Is that my problem or the writer's? I am left supposing it must be mine, since this was a professionally edited book ... but I am not entirely convinced that it is good word choice, even if it is not actually wrong.

This brings to mind what Stephen King talks about in "On Writing": ESP between the reader and the writer. I interpret that as being able to use words and phrases that work with the associations the readers are going to apply to them. Get it right, and the reader does a lot of the work for you, get it wrong and you isolate your reader from the story. It's naturally going to be a bit hit and miss, because different upbringing, environment, experience and education is going to leave people with different associations.