a combining form with the general sense “first, principal,” that is prefixed to nouns denoting things that are earliest, most basic, or bottommost (archiblast; archiphoneme; architrave); or denoting individuals who direct or have authority over others of their class, usually named by the base noun (archimandrite; architect).
Also especially before a vowel, arch-.
Origin of archi-
< Greek, combining form akin to archḗ beginning, árchos leader, árchein to be the first, command
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British Dictionary definitions for archi-
a variant of arch-
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
Medicine definitions for archi-
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.