giganewton noun1 •An SI unit of force equal to 10⁹ newtons. Symbol: GNFor example, the as-received 203-micrometer (7.98-mil) fibers had an average tensile strength of 3.59 giganewtons per square meter (521 ksi) with a coefficient of variation of 23.5 percent. — 1976 formsgiganewtons
