Definition of nerve:

part of speech: verb

To give strength or vigour to; to strengthen.

part of speech: noun

One of the network of grey fibrous cords which are carried from the brain as their centre to all parts of the body, forming the organs of sensation and impressions; fortitude; strength; firmness of mind or body; courage; manliness; in bot., one of the fibrous bundles of the combined vascular and cellular tissue ramifying through leaves, & c., like veins or nerves in the animal structure.