ə̇ˈkwiv(ə)lən(t)s, ēˈ- noun
also equiv·a·len·cy -nsē, -si
( plural equivalences also equivalencies )
Etymology: Middle French & Medieval Latin; Middle French equivalence, from Medieval Latin aequivalentia, from Late Latin aequivalent-, aequivalens + Latin -ia -y
1.
a. : the state or property of being equivalent : exchangeability, correspondence
the equivalence of paper money and coins
the equivalence between the hero's career and that of the author
: equatability
the equivalence of mass and energy
: geologic contemporaneity
time equivalency of the Sly Gap to a portion of the Devonian of Iowa is suggested by new paleological evidence — Journal of Geology
b. : an equivalent or an instance of equivalence
a series of logical equivalences
2. logic
a. : sameness in truth value ; specifically : the logical relationship holding between two statements if they are either both true or both false — called also material equivalence ; compare biconditional
b. : mutual deducibility or reciprocal entailment ; specifically : the relationship holding between two statements if to affirm one and to deny the other would result in a contradiction — called also logical equivalence, strict equivalence
3. : equality in metrical value of a regular foot and one in which there are substitutions (as of a long syllable for two short syllables in quantitative verse or of two or more light unaccented syllables for the normal unaccented syllable in accentual or syllabic verse)