2 : 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
3 : (of a solution) concentration expressed in gram equivalents of solute per liter
4 : the cardinal compass point that is at 0 or 360 degrees
5 : a unit of force equal to the force that imparts an acceleration of 1 m/sec/sec to a mass of 1 kilogram; equal to 100,000 dynes