fellow Definition

1. A companion or equal.

Thesaurus: associate, peer, colleague, comrade, brother, co-worker, equal, partner, counterpart.
2a. A man or boy, sometimes used dismissively;

Thesaurus: youth, lad, boy, adolescent, cadet, juvenile, youngster, teenager, chap, guy.
Form: fella (also colloq)
Form: fellah
Form: feller
2b. A boyfriend.

Form: fella (also colloq)
Form: fellah
Form: feller
3. A senior member of a college or university; a member of the governing body of a college or university.
4. A postgraduate research student financed by a fellowship.
5. A member of any of many learned societies.

Example: Fellow of the Royal Society of Edinburgh
Form: Fellow
6. One of a pair.

Example: one sock on the chair, its fellow on the floor
7. Relating to a person in the same situation or condition as oneself, or having the same status, etc.

Example: a fellow citizen
Example: a fellow worker
Example: a fellow countryman