[CURB sb. 8, 9.] A curvilinear wall-plate at the springing of a dome, etc.; = CURB 9 a, b; also, the plate or frame round the mouth of a well, etc.; the horizontal timber at the junction of the upper and lower slopes of a curb-roof.
1819. P. Nicholson, Archit. Dict., I. 308. The wall-plate of a circular or elliptically ribbed dome, is termed a curb-plate, as also the horizontal rib at the top, on which the vertical ribs terminate.
1860. J. Newlands, Carpenter & Joiner’s Assist., 257. Curb-plate … the circular frame of a well.
