What is another word for corrugations?
Pronunciation: [kˌɒɹuːɡˈe͡ɪʃənz] (IPA) 
Corrugations are a series of ridges or grooves that are characterized by parallel ridges or furrows. Synonyms for corrugations include folds, creases, ripples, pleats, undulations, crinkles, waves, flutes, grooves, and lines. Folds refer to bends or wrinkles in a surface that create irregular shapes or contours. Creases are sharp lines or furrows that are often caused by a folding or crumpling of a surface. Ripple is a series of small waves or undulating movements that create a corrugated effect. Pleats are folds or creases that are set into a fabric to create a decorative element. Undulations are smooth, flowing curves or intermittent rises and dips. Crinkles are small, irregular wrinkles or furrows. Waves are long swells or undulations that roll across a surface.
