seˈrāshən noun
( -s )
Etymology: serrate (II) + -ion
1. : the condition of being serrate
the continual serration of the pine forest — John Ruskin
2.
a. : a formation resembling the toothed edge of a saw
mountains receding in serrations to the west
b. serrations plural : the fine scales projecting from the surface of wool fiber
3. : one of the teeth in a serrate margin
a dial with two hundred serrations