WordNet sense 1 (the cardinal number that is the product of 10 and 100):

g, grand, k, thou, thousand, yard, chiliad, thou, one thousand

WordNet sense 2 (the basic unit of length adopted under the Systeme International d'Unites (approximately 1.094 yards)):

meter, metre

WordNet sense 3 (the 13th letter of the Roman alphabet):

letter m

WordNet sense 4 (concentration measured by the number of moles of solute per liter of solution):

molarity, molar concentration

WordNet sense 5 (being or denoting a numerical quantity but not order):

cardinal