Term: nitrogen: a common nonmetallic element that is normally a colorless odorless tasteless inert diatomic gas; constitutes 78 percent of the atmosphere by volume; a constituent of all living tissues
Broader: chemical element: any of the more than 100 known substances (of which 92 occur naturally) that cannot be separated into simpler substances and that singly or in combination constitute all matter | Unrelated: cervicofacial actinomycosis: the commonest and least severe form of actinomycosis; affects the face and neck regions