per

¹

[ pur; unstressed per ]

preposition

1. for each; for every:

   Membership costs ten dollars per year. This cloth is two dollars per yard.

2. by means of; by; through:

   I am sending the recipe per messenger.

3. Also . according to; in accordance with:

   I delivered the box per your instructions.

   He managed to monopolize the meeting, per usual.

adverb

1. Informal. each; for each one:

   The charge for window-washing was five dollars per.

per-

²

1. a prefix meaning “through,” “thoroughly,” “utterly,” “very”: pervert; pervade; perfect.
2. Chemistry. a prefix used in the names of inorganic acids and their salts that possess the maximum amount of the element specified in the base word: percarbonic (H 2 C 2 O 5 ), permanganic (HMnO 4 ), persulfuric (H 2 S 2 O 8 ), acids; potassium permanganate (KMnO 4 ); potassium persulfate (K 2 S 2 O 8 ).

per.

³

abbreviation for

1. percentile.
2. period.
3. person.

Per.

⁴

abbreviation for

1. Persia.
2. Persian.

per

¹

/ pə; pɜː /

determiner

1. for every

   three pence per pound

preposition

1. (esp in some Latin phrases) by; through
2. as per
   according to

   as per specifications

3. as per usual informal.
   as usual

PER

²

abbreviation for

1. Professional Employment Register

per-

³

prefix

1. through

   pervade

2. throughout

   perennial

3. away, beyond

   perfidy

4. completely, throughly

   perplex

5. (intensifier)

   perfervid

6. indicating that a chemical compound contains a high proportion of a specified element

   peroxide

   perchloride

7. indicating that a chemical element is in a higher than usual state of oxidation

   perchlorate

   permanganate

8. not in technical usage a variant of peroxy-

   persulphuric acid

Usage Note

Per meaning a or an or for each occurs chiefly in technical or statistical contexts: miles per gallon; work-hours per week; feet per second; gallons of beer per person per year. It is also common in sports commentary: He averaged 16 points per quarter. Per is sometimes criticized in business writing in the sense “according to” and is rare in literary writing.

Word History and Origins

Origin of per¹

First recorded in 1580–90; from Latin: “through, by, for, for each”; for

Origin of per²

From Latin, combining form of per, and used as an intensive; per

Word History and Origins

Origin of per¹

C15: from Latin: by, for each

Origin of per²

from Latin per through