Arch. A center or centering used in building an arch, when head-room is required above the springing line, to allow passage through during the time of building.
1841. Brees, Gloss of Civ. Eng., 52. Where head-room is left above the springing of the arches, such centres are termed cocket-centres.
c. 1858. A. P. S. Dict. of Archit., II. C. 58. Where a level tie-beam is omitted … such a centre is called a cocket centre.
