| Noun | 1. | anterior horn - one of two the two roots of a spinal nerve that passes ventrally from the spinal cord and that consists of motor fibers efferent, efferent nerve, motor nerve - a nerve that conveys impulses toward or to muscles or glands nervus spinalis, spinal nerve - any of the 31 pairs of nerves emerging from each side of the spinal cord (each attached to the cord by two roots: ventral and dorsal) |