noun 1. 1 (def 1).
noun, Cell Biology, Physiology. 1. a motor neuron and the muscle fibers innervated by its axon. motor unit n. A single somatic motor neuron and the group of muscle fibers innervated by it.
- Motor urgency
motor urgency n. Urgent desire to empty the urinary bladder due to overactive detrusor function.
noun, British. 1. a motor truck, especially one enclosed to protect the cargo.