\▐riŋ-kәl\ n [ME, back-form. fr. wrinkled twisted, winding, prob. fr. OE gewrinclod, pp. of gewrinclian to wind, fr. ge-, perfective prefix + -wrinclian (akin to wrencan to wrench] (15c) (1) An imperfection in reinforced plastics that has the appearance of a wave molded into one or more plies of fabric or other reinforcing material (ASTM D 883). (2) In a plastic film or coated cloth, an inadvertent crease.