(1):

(n.) 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.

(2):

(n.) The condition of being equivalent or equal; equality of worth, value, signification, or force; as, an equivalence of definitions.

(3):

(n.) The degree of combining power as determined by relative weight. See Equivalent, n., 2.

(4):

(v. t.) To be equivalent or equal to; to counterbalance.

(5):

(n.) Equal power or force; equivalent amount.