a member of a learned society
"he was elected a fellow of the American Physiological Association"
A colleague or partner.
"The fellow who helped me fix the engine was a real pro at his trade."
In plain English: A fellow is simply another person who is part of the same group or situation as you.
"The fellow helped me move the heavy boxes up the stairs."
Usage: Use "fellow" as a noun to refer to a person who shares your work, interests, or group membership, such as a fellow student or a fellow traveler. It functions as a common noun that can stand alone or be combined with another word to specify the type of association.
To suit with; to pair with; to match.
"The designer sought a fabric that would fellow perfectly with the bold colors of his sketches."
In plain English: To fellow someone means to make them feel like they belong with you by treating them as an equal friend.
"The two brothers decided to work together on their shared farm project."
Usage: Do not use "fellow" as a verb in modern English, as this usage is archaic and rarely understood today. Instead, use verbs like "match," "pair," or "coordinate" to express the idea of making things suit one another.
The word fellow entered English in the Middle Ages as a term for a companion or good friend. It ultimately traces back to Old Norse roots meaning "joint venture" or "partnership," originally describing people who laid their property together.