Meaning of molecular weight

molec'ular weight'

Pronunciation: [key]
  1. the average weight of a molecule of an element or compound measured in units once based on the weight of one hydrogen atom taken as the standard or on the weight of an oxygen atom, but after 1961 based on the weight of the carbon-12 atom; the sum of the atomic weights of all the atoms in a molecule. Abbr.: mol. wt. Also called
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.