Tangential is an adjective that means digressive.

The Latin word tangere (tan JAIR ay) means ‘to touch.’ A tangent is a straight line that touches a curve at a single point. It could be said that a tangential speech touches on points in a different sense.

Rob really needs to stop being so digressive in his morning speeches. By the time he’s finished touching on everything he needs to say, the day is half over.