Definition of Fellow servant
One who works for and is controlled by the same employer; a co-worker. Walsh v. Eubanks, 183 Ark. 34, 34 S.W.2d 762, 764. Those engaged in the same type of work, under the control of a common employer. Employees who derive authority and compensation from the same common employer, and are engaged in the same general business. Cactus Drilling Co. v. Williams, Tex.Civ.App., 525 S.W.2d 902, 910. When persons are employed and paid by the same employer, and their duties are such as to bring them into such relation that negligence of one in doing his work may injure other in performance of his, then they are engaged in the same common businesses, and are "fellow servants.” See also Employee; Fellow servant rule.
That's the definition of Fellow servant in Black's Law Dictionary 6th Edition. Courtesy of Cekhukum.com.