a combining form with the meanings “large, great, grand,” “abnormally large,” used in the formation of compound words: megalopolis; megalocardia.
Also especially before a vowel, megal-.
Compare mega-.

Origin of megalo-

< Greek, combining form of megal- (stem of mégas) great, large Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for megalo-


before a vowel megal-

combining form

indicating greatness, or abnormal sizemegalopolis; megaloblast

Word Origin for megalo-

from Greek megas great
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 megalo-



Large; of exaggerated size or greatness:megalocephaly.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.