{s} of a chemical compound which has the same number and kind of atoms as another but differs in structural arrangement (Chemistry)
having the same elements united in the same proportions by weight, and with the same molecular weight, but with a different structure or arrangement of the ultimate parts; as, ethyl alcohol and methyl ether are isomeric (metameric) with each other in this sense
having the same elements united in the same proportion by weight, but with different molecular weights; as, acetylene and benzine are isomeric (polymeric) with each other in this sense
Having the same percentage composition; said of two or more different substances which contain the same ingredients in the same proportions by weight, often used with with