WordNet sense 1 (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):

nitrogen

WordNet sense 2 (the cardinal compass point that is at 0 or 360 degrees):

north, northward, due north

WordNet sense 3 (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):

newton

WordNet sense 4 ((of a solution) concentration expressed in gram equivalents of solute per liter):

normality

WordNet sense 5 (the 14th letter of the Roman alphabet):

letter n