Definition of "buttinsky"

Well, all right then! If you think I'm a buttinsky, then I'll just butt in!

1922, Sinclair Lewis, chapter XX, in Babbitt, New York, N.Y.: Harcourt, Brace and Company, section I, page 252

"Shut up, Garrett. I never," said Mr. Tallboy, extricating himself from Garrett's grasp and giving him a playful punch in the wind, "in my life, met with such a bunch of buttinskis as you are in this department. Nothing is sacred to you, not even a man's business correspondence."

1933, Dorothy L[eigh] Sayers, “Murder Must Advertise. Chapter 4: Remarkable Acrobatics of a Harlequin.”, in The Five Red Herrings (Suspicious Characters): And Murder Must Advertise, Garden City, N.Y.: Nelson Doubleday, page 357

It is never pleasant for a man of sensibility to find himself regarded as a buttinski and a trailing arbutus, and it was thus, I could see at a g., that Wilbert Cream was pencilling me in.

1960, P[elham] G[renville] Wodehouse, chapter V, in Jeeves in the Offing, London: Herbert Jenkins, page 50