grok v.

"understand empathically," 1961, an arbitrary formation by U.S. science fiction writer Robert A. Heinlein (1907-1988) in his book "Stranger in a Strange Land." In the book it is a transliteration of a Martian word and is said to mean etymologically "to drink." It attained popular use in 1960s-70s counterculture but is perhaps obsolete now except in internet technology circles.