C-c C-u is bound to `slime-undefine-function`, though it prompts you for the name of the function and doesn't determine it by the present context. `slime-uninte

C-c C-u is bound to `slime-undefine-function`, though it prompts you for the name of the function and doesn't determine it by the present context. `slime-unintern-symbol` is also present but not bound by default and also prompts for the name.