I'm plotting and worldbuilding for a fantasy series. Like many writers of the genre, I've been working on a fantasy language (I am not putting forth the effort to make it a true conlang, I have neither the time nor the ability) for parts of the worldbuilding. It mostly pertains to names of creatures and the races, and applies to some of the naming conventions of the characters. So it relates almost entirely on the actual fantastical elements of the story rather than language generation.
As I've been working on this, I've wondered…. can these fantasy names be too much? Especially if the fantasy language isn't based on Greek/Latin (which would be more easily understood by English speakers just by virtue of having familiar roots), it seems as though the unusual words can be distracting to a first-time reader.
Personally, I think a lot of it has to do with how well the writer integrates the fantasy language into the text. When I'm reading, if the author introduces a bunch of new words that get no explanation and I can't suss out their meaning via knowledge of suffixes, prefixes, etc., it puts me off the book because it's too confusing at the start. But then you can have the opposite problem, where the author spends the first chapter of the book explaining every single new thing and the reader feels overwhelmed with all the new information.
I think a big problem is that it can be hard to define a new term while keeping the reader immersed in the fantasy. As an example from my own work, Vetëtijak is the word for the race of humans that have the ability to produce electricity from their blood. If I just TELL the reader that, it can seem forced and pedantic. However, if I introduce it in the following manner…
"The Vetëtijak pricked her finger, pulling on the magic within her veins to create a crackle of electricity that jumped from finger to palm and back again. It impressed the travelers surrounding her, but any of her kind could do the same with little effort."
With the right context, anything could be explained in the same way. Still, however, there is a point where it can be too much. Should every fantasy creature get its own name, or is it better to simply say "venomous gnats"? Where should the line be drawn? This is where I think people who write within what I would call the usual mythos have a bit of a leg up. You can throw in elves, kelpies, mermaids, dragons, what have you, and barely have to explain anything because the average reader will have a general idea of what you mean. You'd only have to explain what makes your interpretation different, if anything.
So how do YOU incorporate fantasy language into your work? What authors do you think do a good or bad job of introducing new words and concepts? At what point do you find there to be too many fantasy words? Note that this ISN'T about the creation of conlangs; authors like Tolkien and George R.R. Martin are admirable in their ability to do that, but they also pull very heavily from stereotypical European mythos when it comes to their actual fantasy elements. The amount of NEW concepts is lower than, say, Phillip Pullman's His Dark Materials series where the introduction of daemons, panserbjørne, Mulefa, etc. requires more explanation than, say, the dragons, dire wolves, ogres, etc.