Grok is a neologism coined by the American writer Robert A. Heinlein in his 1961 science fiction novel Stranger in a Strange Land. The Oxford English Dictionary summarizes the meaning of grok as "to understand intuitively or by empathy, to establish rapport with", and "to empathize or communicate sympathetically (with); also, to experience enjoyment". However, Heinlein's original concept, of a human who comes to Earth in early adulthood after being born on the planet Mars, is far more nuanced.