Function: dynamic-completion-mode

Toggle dynamic word-completion on or off.
With a prefix argument ARG, enable the mode if ARG is positive,
and disable it otherwise. If called from Lisp, enable the mode
if ARG is omitted or nil.

(fn &optional ARG)

Variable: dynamic-completion-mode

Non-nil if Dynamic-Completion mode is enabled.
See the command `dynamic-completion-mode' for a description of this minor mode.
Setting this variable directly does not take effect;
either customize it (see the info node `Easy Customization')
or call the function `dynamic-completion-mode'.