(adj) describing a random statement or conclusion that has nothing to do with the statements made prior to it.
Several family members are discussing what to have for supper: "spaghetti? hot dogs?"
when Bill Doe says, "we should hire rodeo camel trainers to help us uncover the secrets of the Bermuda triangle!!"
His statement does not relate to any of the previous statements, and thus is "Non Sequiturious."