per-

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

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British Dictionary definitions for per-

per-

prefix

throughpervade
throughoutperennial
away, beyondperfidy
completely, throughlyperplex
(intensifier)perfervid
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

Word Origin for per-

from Latin per through

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

Word Origin and History for per-

word-forming element meaning "through, throughout; thoroughly; entirely, utterly," from Latin preposition per (see per (prep.)).

per- in Medicine

per-

pref.

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.