Today's word comes from Free Rice:
Grok comes from Robert A. Heinlein's 1961 classic science fiction book, "Stranger in a Strange Land." According to Wikipedia, "grok" is derived from the Martian word meaning "to drink." It is basically defined as "to understand," but really is more than that. It means to understand so deeply as to become one with, to merge, to meld with, to lose oneself in the experience.
Grok. To understand completely. Use it in a sentence. I dare you.