use one's head

:  the act or practice of employing something :  employment, application

:  the fact or state of being used

:  a method or manner of employing or applying something

:  accustom, habituate

:  to put into action or service :  avail oneself of :  employ

:  to consume or take (liquor, drugs, etc.) regularly

:  the upper or anterior division of the animal body that contains the brain, the chief sense organs, and the mouth

:  the seat of the intellect :  mind

:  a person with respect to mental qualities

:  of, relating to, or intended for the upper or anterior division of the animal body that contains the brain, the chief sense organs, and the mouth :  of, relating to, or intended for the head (see ¹head 1)

:  principal, chief

:  located at the end that is upper or higher :  situated at the head (see ¹head 5a)

:  behead

:  to put the striking part of a weapon, tool, or implement on :  fit a head (see ¹head 9b) to

:  to form the uppermost extremity or projecting part of :  to form the head or top of