An extremely annoying or overplayed song on the radio. This definition comes from dialogue in the film Live Free or Die Hard when John McClane turns on the classic radio station and the song 'Fortunate Son' by Creedence Clearwater Revival is playing:
John McClane: You don't like Creedence?
Matt Farrell: This is like having a pinecone shoved in my ass.
('Clumsy' starts playing) "Not this pinecone again!"
"What's that new pinecone by Avril Lavigne called?"
"'Gimme More' is such a huge pinecone!"