This is the 9263rd most frequent French word.
cou
Neck.
In this sentence, 'cou' refers to the anatomical part of the body, the neck.
Il a mis une écharpe autour de son cou.
He put a scarf around his neck.
Here, 'cou' again denotes the body part 'neck' and is used as the object of action.
Elle se tient le cou après avoir été blessée.
She is holding her neck after being injured.
In this example, 'cou' is used metaphorically to describe the narrow part of a bottle which resembles a neck.