Answer
Ghuluww is the Arabic term for exaggeration or excessive veneration. In the Twelver context, it refers to the tendency of some adherents to view the Imams as infallible, divinely inspired beings. Musa al-Kazim, the sixth Imam, was a strong opponent of Ghuluww and worked to eradicate it from Twelver thought. He preached against the idea that the Imams were divine and emphasized their humanity.