From The Collaborative International Dictionary of English v.0.48 [gcide]:
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.
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2. To form into ridges with the plow, as land.
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3. To wrinkle. "With a forehead ridged." --Cowper.
[1913 Webster]
From WordNet (r) 3.0 (2006) [wn]:
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]