keymapp

keymapp is a built-in function in `C source code'.

(keymapp OBJECT)

Return t if OBJECT is a keymap.

A keymap is a list (keymap . ALIST),
or a symbol whose function definition is itself a keymap.
ALIST elements look like (CHAR . DEFN) or (SYMBOL . DEFN);
a vector of densely packed bindings for small character codes
is also allowed as an element.