Definition of fellow
2a
: an equal in rank, power, or character : peer
discussions among a group of fellows from the nearby Los Alamos National Laboratory— Roger Lewin
b
: one of a pair : mate
3
: a member of a group having common characteristics
specifically
: a member of an incorporated literary or scientific society
a fellow of the American College of Surgeons
4a
obsolete
: a person of one of the lower social classes
b
archaic
: a worthless man or boy
5
: an incorporated member of a college or collegiate foundation especially in a British university
6
: a person appointed to a position granting a stipend and allowing for advanced study or research