Meaning of EQUIVALENCE in English

EQUIVALENCE

[equiv.a.lence] n (ca. 1541) 1 a: the state or property of being equivalent b: the relation holding between two statements if they are either both true or both false so that to affirm one and to deny the other would result in a contradiction

2: a presentation of terms as equivalent

3: equality in metrical value of a regular foot and one in which there are substitutions

Merriam-Webster English vocab.      Английский словарь Merriam Webster.