sb. Arch. [f. CUSP + -ING: cf. coving, roofing, etc.] A formation consisting of cusps; cusp-work.
1860. G. E. Street, in Archæol. Cant., III. 124. The cusping was let into a groove.
1870. F. R. Wilson, Ch. Lindisf., 101. It has five lights, the cuspings of which … are early.
