equivalent weight

noun Chemistry.

1. the combining power, especially in grams (gram equivalent), of an element or compound, equivalent to hydrogen as a standard of 1.00797 or oxygen as a standard of 8; the atomic weight divided by the valence.

noun

1. the weight of an element or compound that will combine with or displace 8 grams of oxygen or 1.007 97 grams of hydrogenAlso called: gram equivalent