- 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
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
before a vowel tetr-
Word Origin and History for tetra-
word-forming element meaning "four," from Greek tetra-, combining form of tettares, tessares "four" (see four).
Online Etymology Dictionary, © 2010 Douglas Harper
- Composed of or containing four atoms, molecules, or groups:tetrasaccharide.