# equivalent

Pronunciation: say "i-KWIV-uh-luhnt" /ɪˈkwɪvələnt/

## Adjective

1. Similar or nearly identical to something else in value, meaning, or effect: virtually equal.
   - Simple: Equal or nearly equal to another thing in value, meaning, or effect.
   - _Her new job offers a salary equivalent to what she earned abroad._
   - _The committee ruled the two qualifications equivalent for admission purposes._
3. Of two sets, having a one-to-one correspondence between their members.
   - Simple: Of two sets, having items that match up one to one with none left over.
   - _The set of vowels and the set {1,2,3,4,5} are equivalent, since each letter pairs with one number._
   - _Two sets are equivalent precisely when their members can be paired off one to one._
4. Having an equal capacity to combine chemically with other substances.
   - Simple: Able to combine with the same amount of another substance.
   - _Chemists treated the two reagents as equivalent because each combined with the same quantity of acid._
   - _Hydrogen and a single charge of chlorine are equivalent in combining power._
6. Of magnitudes, equal in measure but not able to be laid exactly over one another.
   - Simple: Of shapes, having the same area or size but not the same form.
   - _A parallelogram and a triangle on the same base may be equivalent though differently shaped._
   - _The two figures are equivalent in area but cannot be superimposed._
7. Of a map projection, preserving area so that regions appear in their correct relative sizes.
   - Simple: Of a map, showing every region at its true relative size.
   - _The atlas used an equivalent projection to compare the true sizes of continents._
   - _On an equivalent map, Greenland no longer dwarfs Africa._
8. Of elements, related by an equivalence relation, so that they count as belonging to the same class.
   - Simple: Of two things, linked by a rule that treats them as the same in some way.
   - _Integers that differ by a multiple of twelve are equivalent under arithmetic modulo twelve._
   - _Two elements are equivalent when the relation places them in the same class._
9. Of two categories, related by a pair of functors so that one is essentially a relabeling of the other.
   - Simple: Of two systems, so alike that one is basically a renaming of the other.
   - _The category of Boolean algebras and a category of certain spaces turn out to be equivalent._
   - _Two categories are equivalent when functors connect them with no loss of structure._

## Noun

2. Something that is virtually equal to another thing, or has the same value, force, or effect.
   - Simple: A thing that is almost equal to another in value, force, or effect.
   - _Engineers searched for a cheaper equivalent that would withstand the same heat._
   - _In ancient trade, a measure of salt served as the equivalent of currency._
5. The mass of a substance that combines with or replaces a standard amount of another, known as its equivalent weight.
   - Simple: The amount of a substance that combines with or replaces a fixed amount of another.
   - _To balance the reaction, add one equivalent of base for each equivalent of acid._
   - _The chemist calculated the equivalent of the unknown salt from the titration data._

## Other meanings

- (verb) To make one thing equivalent to another, or simply to be equal to it.

## Origin

From Latin aequivalentem, the accusative of aequivalēns, the present participle of aequivaleō ("I am equivalent, have equal power"). It can be analyzed as equi- plus -valent.

Source: DictionaryAI, https://dictionaryai.com/define/equivalent (written from Wiktionary data, CC BY-SA 4.0: https://creativecommons.org/licenses/by-sa/4.0/).