bursa (n.)youdaoicibaDictYouDict[bursa 词源字典]
by 1788 as an English word in physiology, shortened from medieval Latin bursa mucosa "mucus pouch," from Medieval Latin bursa "bag, purse," from Late Latin bursa, variant of byrsa "hide," from Greek byrsa "hide, skin, wineskin, drum," which is of unknown origin; compare purse (n.).[bursa etymology, bursa origin, 英语词源]