Definitions for "Leger line"
Keywords:  staff, clefs, soprano, soloists, hike
short line which indicates the pitch of a note above or below the five-line staff.
a short line added to a note to signify it lies beyond the expanse of the staff (i.e. middle C lies on a leger line between the bass and treble clefs)
another device by which soprano soloists hike up their fee, creating notes too high for the human ear to distinguish