the world > space > shape > unevenness > projection or prominence > corrugation > corrugate [verb (transitive)] > ridge > minutely > the edge of something (2)
transitive. To pleat or frill like a ruff; to frill the edge of. Also in extended use. Obsolete.
To press into folds or waves. transitive. To compress into small regular folds or ridges; to corrugate; to frill.