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supinator

American  
[soo-puh-ney-ter] / ˈsu pəˌneɪ tər /

noun

Anatomy.
  1. a muscle used in supination.


supinator British  
/ ˈsuːpɪˌneɪtə, ˈsjuː- /

noun

  1. anatomy the muscle of the forearm that can produce the motion of supination

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of supinator

From New Latin, dating back to 1605–15; supinate, -tor