1) Having crests 2) Like some mountains 3) Rippled 
• (a.) Having a ridge or ridges; rising in a ridge.
Ridg'y adjective Having a ridge or ridges; rising in a ridge. 'Lifted on a ridgy wave.' Pope. 
Subway car with corrugated, stainless steel sides, unsuitable for graffiti. Writers did mainly two-color throwups and some top-to-bottom throwups (one color and silver because silver was hard to buff) on these types of cars. Ridgys ran in Brooklyn.
Subway car with corrugated, stainless steel sides, unsuitable for graffiti. Writers did mainly two-color throwups and some top-to-bottom throwups (one color and silver because silver was hard to buff) on these types of cars. Ridgys ran in Brooklyn.