Mataglap -- an Indonesian word meaning "dark eye" or, probably, "dilated eye." It is an indication that someone is about to go berserk and start killing people at random. Used in Walter Jon Williams' novel Aristoi as the name of a berserk form of nanotechnology that devoured the planet, but also used by my favourite writer (Nicolas Freeling) to describe people going doolally. Language is such fun….
And I’ve just started on a project: the re-reading of all of my Nicolas Freelings. The language is so rich, though: I overdose on words.