'Inequity' vs. 'Iniquity'

Words that have different meanings but share etymological roots are called doublets. Pairings like warranty and guarantee or platoon and peloton or tulip and turban or grammar and glamour show the flexible, opportunistic, and unruly nature of the evolution of words in English.

The Latin word 'aequus' meaning “level” or “equal” is the base of both 'iniquity' and 'inequity.'

How Do Doublets Occur in English?

Sometimes these are the same word borrowed from the same source language twice, but at different times (as with platoon/peloton). Sometimes these are words that took paths through different languages from the root word to English (as with turban/tulip). And sometimes these were essentially spelling variants that seem to be separating subtly in usage and meaning over time, such as further and farther.

Yet another way that different words can share roots is if one of them descends from an ancient word and the other is formed much later, in English—but from the same ancient parts, having since become part of English morphology. Such is the case for the words inequity and iniquity.

'Inequity' vs. 'Iniquity'

These very similar words have distinct meanings: inequity means “unfairness” or “injustice” and iniquity means “wickedness” or “sin.” And yet it’s clear that these words do sometimes overlap, even in our own dictionary’s definition, since inequity is defined as “injustice” for one of its senses yet iniquity is also defined as “gross injustice” for one of its own. So, given the similarity of these words and the closeness of their meaning in some uses, the question arises: are they truly equal?

Etymologically speaking, if you go back far enough, the answer is yes: equal is the shared root word of these terms. The Latin word aequus meaning “level” or “equal” is the base of both iniquity and inequity.

History of 'Iniquity'

Iniquity is the older word in English, having come through French in the 1300s. The French word iniquité descended directly from the Latin word iniquus, which had the meanings “uneven,” “unequal,” “unjust,” and “wicked.” In English, both Samuel Johnson (in 1755) and Noah Webster (in 1828) define iniquity as “injustice” and “wickedness.” Webster cites the Bible:

Your iniquities have separated between you and your God. Isaiah 59:2.

I was shapen in iniquity. Psalms 51:5.

This word is familiar to English-speaking Catholics from this prayer in the Mass:

Wash me, O Lord, from my iniquity and cleanse me from my sin.

Indeed, iniquity seems to have retained a religious tone, or at least a strong moral component; the adjectives closely associated with iniquity include:

wicked

forgiving

evil

guilty

moral

And the nouns that appear near iniquity in texts make it even more plain that the context is most often religious or biblical:

sin

father

mystery

punishment

lord

righteousness

The single word used most frequently in proximity to iniquity is den, to form the idiom den of iniquity, meaning “a place where immoral or illegal things are done.” This use might also seem biblical, but the actual phrase used in the English Bible is “den of robbers” or “den of thieves.” However, den of iniquity does certainly appear in religious contexts, and within a few decades of the King James translation:

How many Millions of People may be seen every Lords Day in the streets of Cities, in the Fields and Villages, that make it their constant Practice to profane the Sabbath, by Vanity and idlenesse, besides those Children of Darknesse, which are already in the Suburbs of Hell, who are then at their Pots and Pipes, in their Dens of Iniquity!
– Thomas Willis, A Word in Season, 1659

Even in pop culture, the term is used in Biblical contexts: it’s in the made-up quotation recited by Jules, the character played by Samuel L. Jackson in “Pulp Fiction”:

The path of the righteous man is beset on all sides by the iniquities of the selfish and the tyranny of evil men.

History of 'Inequity'

Inequity was constructed in English of the Latin-based prefix in- and the English word equity, which entered the language in the 1300s. If you think that it’s a bit strange that this word was constructed in English from the same parts that, in Latin, comprised the ancestor of iniquity, you’d be correct, but consider how much more strange it is that we also have the word inequality, which is pretty much the same parts making up a slightly different word. Keep in mind also that iquity doesn’t exist as an English word.

No one said English would be logical.

The fact is, the original Latin word could have split into several meanings in English—polysemy is a thing, after all—but instead, it separated itself both semantically (by meaning) and morphologically (by form), along the same lines as equity and equality, since equity most often denotes ideas of “justice” or “fairness” and equality denotes ideas of “sameness” or “evenness.”

Adjectives used in close proximity to inequity are:

social

economic

racial

educational

global

And the nouns used with inequity make it clear that the issues it connects most with are social and economic:

gender

health

education

injustice

pay

It should come as no surprise that iniquity and inequity are sometimes confused with each other, a confusion that goes back to the very beginning, since it’s clear that, especially before the advent of standard dictionaries in the 17th and 18th centuries, the spelling inequity was used to mean “wickedness” before it came into use meaning “injustice”—in other words, these words were at one time spelling variants of each other.

Given how much these words have in common, it’s notable that their respective adjective forms have followed different morphological paths and are therefore less likely to be mistaken for each other: inequitable and iniquitous.

Today, unsurprisingly, inequity is used much more frequently than iniquity, but the words are clearly sometimes confused for each other. Perhaps this is proof that, even when they intersect in etymology and usage, all words are not created equal.