Webster’s Revised Unabridged Dictionary · 1913
Equivalence
E·quiv′a·lence (ē·kwĭv′ȧ·lens), n. [Cf. F. équivalence, LL. aequivalentia.] 1. The condition of being equivalent or equal; equality of worth, value, signification, or force; as, an equivalence of definitions.
2. Equal power or force; equivalent amount.
3. (Chem.) (a) 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. (b) The degree of combining power as determined by relative weight. See Equivalent, n., 2. [R.]
E·quiv′a·lence, v. t. To be equivalent or equal to; to counterbalance. [R.] Sir T. Browne.