a horizontal line between the springs of an arch or dome.
the rise or the angle of the rise of an arch.
Words nearby springing line
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for springing line
Their arches are richly moulded and acutely pointed, the springing-line being rather low down.Bell's Cathedrals: The Cathedral Church of Ripon|Cecil Walter Charles Hallett