Clap, subst., 1) striking together of hands to express applause: whose shouts and --s outvoice the deep-mouthed sea, H5 V, Chor. As V, 3, 11 every one with --s can sound 'Our heir apparent is a king,' Per. III Prol. 36.
2) At a c. == at a blow: “fifty of my followers at a c.” Lr. I, 4, 316.