Headless

adjective

1. Without a head; decapitated.

   "How did the headless horseman see to chase Ichabod?"

2. Without leadership.

   "The headless army blundered along after the death of their general, accomplishing nothing."

3. (of a phrase or compound) Not having a head morpheme or word.
4. Running without a graphical user interface; running without any attached output device (e.g., monitor) or input device (e.g., keyboard, mouse).
5. (of beer) Without a head of foam.