equal in force, amount, or value
corresponding or virtually identical, esp in effect, function, or meaning
having the same chemical combining capacity
equivalent quantities of two elements
related by an equivalence relation
equivalence noun
equivalently adv
[Middle English via French from late Latin aequivalent-, aequivalens, present part. of aequivalēre to have equal power, from Latin aequi- equi- + valēre to be strong]