Share this entry

bursa of Fabricius Syllabification: bur·sa of Fa·bri·ci·us
Pronunciation: /ˌbərsə əv fəˈbriSH(ē)əs/

Definition of bursa of Fabricius in English:


A glandular sac opening into the cloaca of a bird, producing B cells.
Example sentences
  • Males with large badges have a smaller bursa of Fabricius than do average males.
  • These drugs prevent development of the bursa of Fabricius and so selectively reduce humoral immunocompetence without influencing macrophages or cell-mediated immunity.
  • Birds that possessed a bursa of Fabricius were classified as young birds in their second or third calendar year.


Mid 19th century (in the Latin form bursa Fabricii): from bursa, and a Latinized form of the name of Girolama Fabrici (1533–1619), Italian anatomist.

Definition of bursa of Fabricius in:

Share this entry


What do you find interesting about this word or phrase?

Comments that don't adhere to our Community Guidelines may be moderated or removed.

Get more from Oxford Dictionaries

Subscribe to remove ads and access premium resources

Word of the day fortissimo
Pronunciation: fôrˈtisəˌmō
(especially as a direction) very loud or loudly