(set theory) Any one of the subsets into which an equivalence relation partitions a set, each of these subsets containing all the elements of the set that are equivalent under the equivalence relation.

(set theory) A binary relation that is reflexive, symmetric and transitive.

(physics) any of several principles, in relativity, concerned with the uniformity of physical measurements in different frames of reference

(chemistry) the amount of a substance, in grams, that is numerically equivalent to its equivalent weight

(chemistry) The atomic weight of an element or radical divided by its valence; the molecular weight of a compound divided by its combining power in a specific reaction.

Having row-equivalence

(linear algebra) A relation between two matrices of the same size, such that every row of one matrix is a linear combination of the rows of the other matrix, and vice versa. It is an equivalence relation.

(law, US) A legal rule in most patent systems that allows a court to hold a party liable for patent infringement when the infringing device or process does not fall within the literal scope of a patent claim, but nevertheless is equivalent to the claimed invention.

plural of equivalent weight

plural of equivalence relation