Nervous Juice or Spirit

Nervous Juice or Spirit is a pure, subtil, volatile humour, commonly called the animal spirits; secreted from the arterial blood in the cortical part of the brain, collected in the medulla oblongata, and driven thence by the force of the heart, into the cavities of the nerves, to be by them convey’d throughout the body, for the purposes of sensation and animal motion.

Definition taken from The Universal Etymological English Dictionary, edited by Nathan Bailey (1736)

Nagel * Neˊw Year’s Gift
Muˊsquash [in several parts of America]
Nagel
Nervous Juice or Spirit
Neˊw Year’s Gift
Niˊsey
Non compos mentis [i. e. not of sound understanding or memory]
Noodle
Nudiˊties [in Painting and Sculpture]
Nudipedaˊlia [among the Romans]
Octoˊber [in Painting &c.]