nitrogen
Cross references: 1. element ni.tro.gen \'ni--tr*-j*n\ \ni--'tra:j-*-n*s\ n [F nitrogene, fr. nitr- + -ge'ne -gen] often attrib : a colorless tasteless odorless gaseous element that constitutes 78 perce nt of the atmosphere by volume and is a constituent of all living tissues - ni.trog.e.nous aj