Q: Has the use of “prior” as an adverb gained acceptance? I am seeing it more and more, as in this example from a book on chess: “Why did I play in the Los Angeles Open a month later? I’d said I would, a year prior.”
A: That use of “prior” by itself as an adverb is not recognized in the 10 standard dictionaries we regularly consult.
The dictionaries consider “prior” an adverbial usage only as part of the preposition “prior to,” as in “He made the will prior to his marriage.” In that sentence, “prior to” introduces a prepositional phrase (“prior to his marriage”) that modifies the verb “made.”
As we wrote on our blog in 2007, “prior to” is a preposition that can function as either an adjective or an adverb. We used these examples: “Construction prior to [adjective] 1900 is reviewed prior to [adverb] demolition.” In either case, “previous to” or “before” could be substituted for “prior to.”
So the adverbial use you mention, “I’d said I would, a year prior,” would be more acceptable in this form: “I’d said I would, a year prior to that.”
We’ll have more about “prior to” a bit later. As for “prior,” it’s sometimes used as a noun—meaning a religious official or as short for “prior conviction” or “prior arrest.” But in the sense you’re asking about, it’s defined in standard dictionaries as an adjective (not an adverb).
A usage note in American Heritage has this to say about the use of “prior” as an adjective:
“Though prior usually modifies a noun that comes after it, as in prior approval, it sometimes modifies a noun for a unit of time which precedes it, as in five years prior. These constructions are marginally acceptable when the combination serves as the object of a preposition, as in A gallon of gasoline was $4.29, up 10 cents from the week prior. In our 2014 survey, 51 percent of the Panelists accepted the sentence, with many commenting that they would prefer from the prior week or from the week before.”
The usage note goes on to add this about “prior” as an adverb: “The construction is even less acceptable when it acts as an adverbial modifier: only 29 percent of the Panel approved My cellphone was stolen. I had just bought it two days prior.”
Getting back to “prior to,” American Heritage and Merriam-Webster define the phrase as a preposition synonymous with “before.” M-W says this in a note: “Sometimes termed pompous or affected, prior to is a synonym of before that most often appears in rather formal contexts, such as the annual reports of corporations.” (Longman’s labels the “prior to” usage “formal.”)
The Cambridge Grammar of the English Language includes “prior” in a class of words that are prepositions when their complements are preceded by “to,” as in “prior to this.” Other such prepositions, according to the Cambridge Grammar, include “according,” “subsequent,” “pursuant,” “preparatory,” “next,” “previous,” “owing,” “contrary,” and several more. “For the most part,” the book says, “the to phrase complement is obligatory when these items are prepositions.”
As for its etymology, “prior” was adopted in the early 17th century from the classical Latin prior. To the Romans, the OED says, prior meant “in front, previous, former, earlier, elder, superior, more important.”
In English, Oxford says, “prior” was first used as an adjective, meaning “that precedes in time or order; earlier, former, anterior, antecedent.” The dictionary’s earliest citation is from 1607: “Learned Magitian, skild in hidden Artes, / As well in prior as posterior parts” (The Diuils [Devil’s] Charter, a play by Barnabe Barnes).
In examples like that, the adjective “prior” is attributive—that is, it appears before the noun. But it can also be predicative (appearing after the noun) and in those cases it’s chiefly used “with to,” Oxford says.
Here’s the dictionary’s earliest such use: “I & my predicessouris [predecessors] be indouttitlie [undoubtedly] prior to thame in richt & place of dignitie” (The Acts of the Parliaments of Scotland, 1641).
The adverbial use of “prior to” appeared later in the same century and means “previously to, before, in advance of,” Oxford says. This is the dictionary’s earliest example:
“It was clear, that there was a former Trade, and correspondence betwixt them, prior to the Sons Infeftment.” (From Observations, 1675, Sir George Mackenzie’s commentaries on various Scottish parliamentary acts. “Infeftment” is a term in Scots law, similar to “enfeoffment” in English law, having to do with the investing of a feudal estate or fee.)
In our opinion, both “prior” alone and “prior to” have a lofty, formal sound, and for ordinary use there are better terms, both adjectives and adverbs: “previous,” “previously,” “before,” “earlier,” “in advance,” “preceding,” and so on. Usually, nothing is lost in translation.
However, Merriam-Webster compares the adjectives “prior” and “previous” and detects a slight difference: “previous and prior imply existing or occurring earlier, but prior often adds an implication of greater importance,” and it contrasts the uses with these examples: “a child from a previous marriage” versus “a prior obligation.”