a combining form meaning “billion,” used in the formation of compound words: gigabyte.
Origin of giga-
From the Greek word gígās giant
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
denoting 10 9gigavolt Symbol: G
(in computer technology) denoting 2 30gigabyte
Word Origin for giga-
from Greek gigas giant
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
arbitrary word-forming element meaning "billion" in the metric system, 1947, from Greek gigas "giant" (see giant).
Online Etymology Dictionary, © 2010 Douglas Harper
One billion (109):gigahertz.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
A prefix that means:
One billion (109), as in gigahertz, one billion hertz.
230 (that is, 1,073,741,824), which is the power of 2 closest to a billion, as in gigabyte.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.