equal in wortir or value, force, power, effect, import, and the like; alike in significance and value; of the same import or meaning.-equal in measure but not admitting of superposition; -- applied to magnitudes; as, a square may be equivalent to a triangle.-contemporaneous in origin; as, the equivalent strata of different countries.-something equivalent; that which is equal in value, worth, weight, or force; as, to offer an equivalent for damage done.-that comparative quantity by weight of an element which possesses the same chemical value as other elements, as determined by actual experiment and reference to the same standard. specifically: (a) the comparative proportions by which one element replaces another in any particular compound; thus, as zinc replaces hydrogen in hydrochloric acid, their equivalents are 32.5 and 1. (b) the combining proportion by weight of a substance, or the number expressing this proportion, in any particular compound; as, the equivalents of hydrogen and oxygen in water are respectively 1 and 8, and in hydric dioxide 1 and 16.-a combining unit, whether an atom, a radical, or a molecule; as, in acid salt two or more equivalents of acid unite with one or more equivalents of base.-to make the equivalent to; to equal; equivalence.