Jerk supports heads in private (8)
I believe the answer is:
domestic
'private' is the definition.
(thesaurus)
'jerk supports heads' is the wordplay.
'jerk' becomes 'tic' (jerking movement by the body).
'supports' means one lot of letters go next to another (bottom letters provide a support for the top ones).
'heads' becomes 'domes' (I am not sure about this - if you are sure you should believe this answer much more).
'tic' put after 'domes' is 'DOMESTIC'.
'in' acts as a link.
Can you help me to learn more?
(Other definitions for domestic that I've seen before include "violent incident at home" , "Argument - in the home" , "Relating to the home or family" , "Tame - row - maid" , "Internal; servant" .)