Chucklehead

Chucklehead  is a recurring insult commonly used on Dean and Sam Winchester.

Overview
Bobby used it on Sam and Dean in Are You There, God? It's Me, Dean Winchester

Zachariah used it as a way to tell Dean that he is the true vessel of Michael in Sympathy for the Devil.

Gabriel used it to describe the brothers in Unfinished Business.

Trivia

 * It is a recurring insult in the show.