per

¹ American  

[pur, per] / pɜr, pər /

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 American  

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 O5 ), permanganic (HMnO4 ), persulfuric (H 2 S 2 O8 ), acids; potassium permanganate (KMnO4 ); potassium persulfate (K 2 S 2 O8 ).

---

per. ³ American  

abbreviation

1. percentile.

2. period.

3. person.

---

Per. ⁴ American  

abbreviation

1. Persia.

2. Persian.

---

per- ¹ British  

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

   permanganate

   perchlorate

8. (not in technical usage) a variant of peroxy-

   persulphuric acid

---

per ² British  

/ pə, pɜː /

determiner

1. for every

   three pence per pound

---

preposition

1. (esp in some Latin phrases) by; through

2. according to

   as per specifications

3. informal as usual

PER ³ British  

abbreviation

1. Professional Employment Register

---

Usage

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.

Etymology

Origin of per¹

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

Origin of per-²

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

Example Sentences

However, when the researchers interfered with actin -- a protein that allows cells to contract and move -- hair growth slowed dramatically, dropping by more than 80 per cent.

From Science Daily

Airfares are rising because airlines use an estimated one billion gallons of jet fuel per quarter, or about 25% to 30% of their expenses, and jet fuel prices have increased by $1.20 to $1.50 a gallon this month, said Patrick De Haan, head of petroleum analysis for GasBuddy.

From Barron's

Taxpayers age 65 and older can also claim an additional $6,000 deduction per person, subject to income phase-outs.

From MarketWatch

But if oil stays above $80 per barrel for the year, that extra $800 will go to gas pumps and energy costs instead of other ways Americans could use their refund money, Wilding noted.

From MarketWatch

To shift the needle there, you would have to meaningfully add to supply to replace the 20 million barrels per day being cut off by Iran, and any new production isn’t going to do that.

From Los Angeles Times