One who is excessive in the act of interfering.
(person 1 is happy watching tv)
(person 2 comes in and starts to interfere by changing the channel)
person 1: stop being a van dyke!
In this instance person 2 would be a van dyke.
Where it has derrived from: In Mary Poppins Dick Van Dyke used to interfere during Mary Poppins.
Mary Poppins: (singing)
Dick Van Dyke:Oh its so lovely!!!!!
this would continue until the end of each song.
Van dykes: (a group of van dykes)look at that gang of van dykes!
Van dyked:(to be van dyked)he is getting van dyked!
Van dyking:(to Van dyke) stop van dyking will you!
Van Dyker:(one who van dykes)he's a van dyker!