Southern Hemispheren.1. The half of the earth south of the equator.2. Astronomy The half of the celestial sphere south of the celestial equator.American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.southern hemisphere n (often capitals) 1. (Physical Geography) that half of the earth lying south of the equator2. (Astronomy) astronomy that half of the celestial sphere lying south of the celestial equatorAbbreviation: S hemisphereCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014South?ern Hem?isphere n. the half of the earth between the South Pole and the equator. Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.Southern Hemisphere1. The half of the Earth south of the equator.2. Astronomy The half of the celestial sphere south of the celestial equator.The American Heritage® Student Science Dictionary, Second Edition. Copyright © 2014 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.