1. Essentially rod-shaped with one end thickened or bulbous. 2. A name applied, loosely, to any Gram-positive, asporogenous, pleomorphic rod-shaped bacterium; as such it covers bacteria from a range of genera. 
(ko-ri´nә-form) club-shaped; denoting or resembling organisms of the family Corynebacteriaceae.
having a rodlike or clublike shape.