grok \GRAWK\ , verb;

1.To understand, especially in a profound and intimate way. Slang.

usage: For those who don’t quite grok the Web, it can be an intimidating challenge.
— New York Times, June 1, 1997

Origin: The slang word grok was coined by Robert A. Heinlein in the science fiction novel “Stranger in a Strange Land”, where it is a Martian word meaning literally “to drink” and metaphorically “to be one with”.

via Word of the Day | Dictionary.com.