- a prefix meaning “through,” “thoroughly,” “utterly,” “very”: pervert; pervade; perfect.
- 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 (H2C2O5), permanganic (HMnO4), persulfuric (H2S2O8), acids; potassium permanganate (KMnO4); potassium persulfate (K2S2O8).
Origin of per-
< Latin, combining form of per per, and used as an intensive
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- away, beyondperfidy
- completely, throughlyperplex
- indicating that a chemical compound contains a high proportion of a specified elementperoxide; perchloride
- indicating that a chemical element is in a higher than usual state of oxidationpermanganate; perchlorate
- (not in technical usage) a variant of peroxy- persulphuric acid
from Latin per through
Word Origin and History for per-
word-forming element meaning "through, throughout; thoroughly; entirely, utterly," from Latin preposition per (see per (prep.)).
Online Etymology Dictionary, © 2010 Douglas Harper
- Thoroughly; completely; intensely:perfuse.
- Containing an element in its highest oxidation state:perchloric acid.
- Containing a large or the largest possible proportion of an element:peroxide.
- Containing the peroxy group:peracid.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.