1. To, for, or by each; for every: Gasoline once cost 40 cents per gallon.
2. According to; by: Changes were made to the manuscript per the author's instructions.
3. By means of; through.

1. For each one; apiece: sold the cookies for one dollar per.
2. Per hour: was driving at 60 miles per.

[Latin.]

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.