noun: (literary) The fictional creature of Lewis Carroll's poem, used allusively to refer to fruitless quest or search.
noun: (mathematics) A graph in which every node has three branches, and the edges cannot be coloured in fewer than four colours without two edges of the same colour meeting at a point.
noun: (physics) A fluke or unrepeatable result or detection in an experiment.
noun: A fictional animal in Lewis Carroll’s The Hunting of the Snark.
noun: A ketch built by Jack London named after Lewis Carroll's poem The Hunting of the Snark