corrugate

 
Pronunciation: /ˈkɒrʊgeɪt/

verb

  • contract or cause to contract into wrinkles or folds: [no object]: Micky’s brow corrugated in a simian frown

Origin:

late Middle English: from Latin corrugat- 'wrinkled', from the verb corrugare, from cor- (expressing intensive force) + rugare (from ruga 'a wrinkle')