Plain English Meaning
Tiny tooth-shaped marks on a chart that show where an intersection sits along an airway.
Full Definition
On aeronautical charts, a series of short, tooth-like tick marks drawn along a line — typically a Victor airway — used to identify and locate an intersection along that route.
Context Anchor
Seen on IFR en route charts and instrument procedure charts when a fix or intersection is identified using a reference line from a navigation aid.
Derivation
From Latin 'serra' meaning saw. The marks look like the teeth of a saw blade, which is why they're called serrations.