a combining form meaning “four,” used in the formation of compound words: tetrabranchiate.
Also especially before a vowel, tetr-.

Origin of tetra-

< Greek, combining form of téttara, neuter of téttares four
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British Dictionary definitions for tetra-


before a vowel tetr-

combining form


Word Origin for tetra-

from Greek
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

Medical definitions for tetra-



Composed of or containing four atoms, molecules, or groups:tetrasaccharide.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.