ridged

The sponge pulls this off via its spiral, ridged outer surface that functions like a spiral staircase.

"Some look like bumped, ridged shields, others look like flat shovels," he said.

Cells grew and proliferated on both flat and ridged films.

His fingernails were long and curved and ridged with dirt.

With the intricately hammered texture of a giant ridged potato chip, the cup must surely have cost more man hours than any yachting victory it could have ever been awarded to.