a combining form meaning “outer,” “outside,” “external,” used in the formation of compound words: ectoderm.
Words nearby ecto-
Also especially before a vowel, ect-.
Origin of ecto-
combining form of Greek ektós outside
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
British Dictionary definitions for ecto-
indicating outer, outside, externalectoplasm
Word Origin for ecto-
from Greek ektos outside, from ek, ex out
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
Medicine definitions for ecto-
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.