Definitions
1.AdjectiveSimilar or identical in value, meaning or effect; virtually equal."To burn calories, a thirty-minute jog is equivalent to a couple of hamburgers."
2.AdjectiveOf two sets, having a one-to-one correspondence.
3.AdjectiveRelating to the corresponding elements of an equivalence relation.
4.AdjectiveOf two categories, (informally) such that one is essentially a relabeling of the other; (formally) related by a pair of functors such the composition of the one with the other is naturally isomorphic to the identity functor.
5.AdjectiveHaving the equal ability to combine.
6.AdjectiveOf a map, equal-area.
7.AdjectiveEqual in measure but not admitting of superposition; applied to magnitudes."A square may be equivalent to a triangle."
8.NounAnything that is virtually equal to something else, or has the same value, force, etc.
9.NounAn equivalent weight.
10.VerbTo make equivalent to; to equal.