headless

adj

1. (not-comparable)Without a head (body part).

   “How did the headless horseman see to chase Ichabod?”

2. (not-comparable)Without a head (body part).

   “headless invertebrates”

3. (not-comparable)Without a head (hardware or device feature).

   “a headless nail;   a headless set screw”

4. (not-comparable)Without leadership.

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

   “His forsaken soldiers, being now a headless company, and no longer an army to be feared, obtained nevertheless a reasonable composition from the Carthaginians […]”

5. (not-comparable)Not having a head morpheme or word.
6. (not-comparable)Running without a graphical user interface; running without any attached output device (e.g., monitor) or input device (e.g., keyboard, mouse).

   “/redirect. Used for console redirection in headless servers.”

   “Routers typically run headless, without a keyboard or monitor.”

   “This is not unexpected for a Windows system running as a virtual machine or a headless server,[…]”

7. (not-comparable)Without a head of foam.
8. (not-comparable, obsolete)Heedless.

   “1579, E. K. (Edward Kirke?), Notes on Spenser’s The Shepheardes Calender If any one will rashly blame such his choice of old and unwonted words, him may I more justly blame and condemn, either of witless headiness in judging, or of headless hardiness in condemning.”

   “THENOT: Cuddy, I wot thou kenſt little Good, / So vainly to advance thy headleſs Hood.”

9. (not-comparable, obsolete)Rimless, not having a cartridge case rim (flange).

   “A headless shell doesn't have a flange.”