O

10 ENTRIES FOUND:

O

noun \ˈō\

Definition of O

: the one of the four ABO blood groups characterized by the absence of antigens designated by the letters A and B and by the presence of antibodies against these antigens

Seen & Heard

What made you want to look up O? Please tell us where you read or heard it (including the quote, if possible).

Get Our Free Apps
Voice Search, Favorites,
Word of the Day, and More
Join Us on FB & Twitter
Get the Word of the Day and More