Grok is a slang verb roughly meaning "to understand completely" or more formally intuitive understanding. It is primarily used by counterculturists. The term originated in Robert Heinlein's novel Stranger in a Strange Land, where it is part of the fictional Martian language and introduced to English speakers by a man raised by Martians. In the Martian tongue, it literally means "to drink" but is used in a much wider context. A character in the novel (not the primary user) defines it: "Grok means to understand so thoroughly that the observer becomes a part of the observed—to merge, blend, intermarry, lose identity in group experience. It means almost everything that we mean by religion, philosophy, and science—and it means as little to us (because we are from Earth) as color means to a blind man." The term "Grok" has been used fairly consistently since the mid-1960s however, back in the 80's there was a sketch on "Saturday Night Live" which featured a Star Trek fan with a shirt with this saying. It has been popular ever since!