Let's say I'm writing a sci-fi novel. I want to use a word which another writer has coined, which has become well-recognized outside the original book, for the name of an alien species in my story.
I want to do something akin to this:
Jacob walked in the room, accompanied by Dori, who jumped on the table beside him and began sniffing the book.
"What's that?" said Katie with a frown.
"This is Dori. She's the consulate's grok. She should be able to tell us how old this book is and who had it."
"She's a what?"
Jacob chuckled. "Her species has their own name for themselves, but it's practically impossible to pronounce. What they're best at is — well, they sort of sniff out history. They can read all kinds of things about an object. The history of it, the age, who touched it, how many people touched it —"
"She smells all that?"
"It's not really smelling, but close enough. Anyway, when they first arrived and we found out what they could do, one of the ambassadors is a real Heinlein buff, and she started calling them 'groks.' And it stuck."
Can I get away with that? Considering that "grok" is popular enough to be known outside Stranger in a Strange Land, I'm using it to mean something similar to the coined meaning, it's not an insult or derogatory in any fashion, and I'm citing the coiner of the word right there in dialogue as I introduce the word. Is that considered "fair use"? Or is "grok" so attached to Heinlein that I would still have to get permission?