the condition of being equivalent or equal; equality of worth, value, signification, or force; as, an equivalence of definitions.-equal power or force; equivalent amount.-the quantity of the combining power of an atom, expressed in hydrogen units; the number of hydrogen atoms can combine with, or be exchanged for; valency. see valence.-the degree of combining power as determined by relative weight. see equivalent, n., 2.-to be equivalent or equal to; to counterbalance.