Agreed with the head? (6)
I believe the answer is:
nodded
'agreed' is the definition.
(I've seen this before)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for nodded that I've seen before include "Gave silent assent with head movement" , "Assented with head movement" , "signed agreement" , "Signified agreement" , "Lowered and raised the head" .)