Cobra is the Portuguese word for “snake”. In English and in some other languages, it has been adopted as the name for any of various species of venomous snakes. Most of those species are in the family Elapidae, all of which are venomous. Most of them can spread their neck ribs to form a flattened, widened hood. Not all snakes commonly referred to as cobras are of the same genus, or even in the family Elapidae.