D defs.my
Entry 1 sense Webster, 1913

Corrugation

/(k?r`r?-g?"sh?n)/ · Cor·ru·ga·tion · IPA /ˌkɔɹ.əˈɡeɪ.ʃən/
01 n. The act corrugating; contraction into wrinkles or alternate ridges and grooves.
  1. 1.
    The act corrugating; contraction into wrinkles or alternate ridges and grooves.