a combining form of sphere (planisphere); having a special use in the names of the layers of gases and the like surrounding the earth and other celestial bodies (ionosphere).
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British Dictionary definitions for -sphere
n combining form
having the shape or form of a spherebathysphere
indicating a spherelike enveloping massatmosphere
Derived Forms-spheric, adj combining form
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