jock  
noun uk/dʒɒk/ us/dʒɑːk/
  (PERSON)     
  [ C ] US informal disapproving体育迷 
a person who is extremely enthusiastic about sport
   (UNDERWEAR)     
jocks[ plural ] Australian English informal 男式内裤
a piece of underwear worn by men and boys that covers the area between the waist and the tops of the legs
 Compare: underpants