per mill

American

[pur mil, per] / ˌpɜr ˈmɪl, pər /

Or per mil

adverb

per thousand.

per mill British

/ pə ˈmɪl /

adverb

by the thousand or in each thousand

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of per mill

First recorded in 1900–05

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023