Plain English Meaning
A 360-degree direction circle that shows which way is which. It is used on charts to read headings and bearings, and painted on the ground at airports as a reference for checking aircraft compasses.
Full Definition
A circle, graduated in degrees from 000° to 359°, printed on aeronautical charts and aerodrome surfaces to show direction with reference to magnetic north (or, in some cases, true north).
Context Anchor
Seen on some aviation charts and on airport surfaces used for checking an aircraft compass.
Derivation
From the old practice on mariners' charts of drawing a decorative circle marked with the cardinal directions; the points radiating outward looked like the petals of a rose. Aviation inherited the same idea and the same name.