wig       
noun [ C ] uk/wɪɡ/ us/wɪɡ/
 假发
a covering of artificial hair worn on the head to hide a loss of hair or to cover your own hair
  She was wearing a blonde wig. 她戴着金色的假发。 
 In Britain, judges wear white wigs in court. 在英国,法官在法庭上戴白色的假发。 
 Compare: toupée