Main entry: headless
Definition: not having a head or formed without a head
Usage: the headless horseman; brads are headless nails
Antonyms: headed
Definition: having a head of a specified kind or anything that serves as a head; often used in combination
Main entry: headless, brainless
Definition: not using intelligence
Antonyms: smart
Definition: showing mental alertness and calculation and resourcefulness
Antonyms: intelligent
Definition: having the capacity for thought and reason especially to a high degree