From The Collaborative International Dictionary of English v.0.48 :
Ridge \Ridge\, v. t. [imp. & p. p. Ridged; p. pr. & vb. n. Ridging.] 1. To form a ridge of; to furnish with a ridge or ridges; to make into a ridge or ridges. [1913 Webster] Bristles ranged like those that ridge the back Of chafed wild boars. --Milton. [1913 Webster] 2. To form into ridges with the plow, as land. [1913 Webster] 3. To wrinkle. "With a forehead ridged." --Cowper. [1913 Webster]From WordNet (r) 3.0 (2006) :
ridged adj 1: having a ridge or shaped like a ridge or suggesting the keel of a ship; "a carinate sepal" [syn: ridged, carinate, carinated, keeled]