Just out of curiosity-- I am working on a novel currently and I've wondered whether using other authors' terms for elements for instance such as the Adamantim or meds such as cancer dust, etc considered plagiarizing? Is there a such a thing as copyrighted word? I would hate to finish my book and realize that I have to go back and think of new terms and new definitions for these type of items for that I have no desire to rip anyone off or to be in the wrong. Your feedback is appreciated. Thanks!

Yes, there is, if a specific term or concept was used in a public work, you should get the permission of the author.

For example, Isaac Asimov gave permission to other authors to use his three laws of robotics.

Do you mean adamantium?
I'll bet that Marvel Comics would sue for that one. Yes, it's 'ripping them off.'