This is the 11092nd most frequent Russian word.
головой
The Russian word "головой" means "with (the) head" or "by (the) head," often indicating the use or involvement of the head.
In this sentence, 'головой' (by one's head) is used to indicate an action performed using the head, specifically shaking it as a gesture.
Он покачал головой в знак несогласия.
He shook his head as a sign of disagreement.
Here, 'головой' signifies using one’s head metaphorically to denote logical thinking as opposed to emotional reasoning.
Она думала головой, а не сердцем.
She thought with her head, not with her heart.
In this context, 'головой' means 'with his head,' describing a physical action or impact involving the head.