WordNet sense 1 (a purine base found in DNA and RNA; pairs with cytosine):

guanine

WordNet sense 2 (one of the four nucleotides used in building DNA; all four nucleotides have a common phosphate group and a sugar (ribose)):

deoxyguanosine monophosphate

WordNet sense 3 (the cardinal number that is the product of 10 and 100):

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

WordNet sense 4 (a metric unit of weight equal to one thousandth of a kilogram):

gram, gm, gramme

WordNet sense 5 (a unit of force equal to the force exerted by gravity; used to indicate the force to which a body is subjected when it is accelerated):

gee, g-force

WordNet sense 6 (a unit of information equal to one billion (1,073,741,824) bytes or 1024 megabytes):

gigabyte, GB

WordNet sense 7 ((physics) the universal constant relating force to mass and distance in Newton's law of gravitation):

gravitational constant, constant of gravitation, universal gravitational constant

WordNet sense 8 (the 7th letter of the Roman alphabet):

letter g