a prefix appearing in loanwords from Greek, where it meant “under” (hypostasis); on this model used, especially as opposed to hyper-, in the formation of compound words (hypothyroid).
Also especially before a vowel, hyp-.
Origin of hypo-
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
before a vowel hyp-
under, beneath, or belowhypodermic
lower; at a lower pointhypogastrium
(in medicine) denoting a deficiency or an abnormally low levelhypothyroid; hypoglycaemia
incomplete or partialhypoplasia
indicating that a chemical compound contains an element in a lower oxidation state than usualhypochlorous acid
Word Origin for hypo-
from Greek, from hupo under
indicating a plagal mode in musicHypodorian
Word Origin for Hypo-
from Greek: beneath (it lies a fourth below the corresponding authentic mode)
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
word-forming element meaning "under, beneath" (in chemistry, indicating a lesser oxidation), from hypo-, comb. form of Greek hypo (prep. and adverb) "under," from PIE *upo- "under, up from under, over" (see sub-).
Online Etymology Dictionary, © 2010 Douglas Harper
Below; beneath; under:hypochondriac.
Less than normal; deficient:hypofunction.
In the lowest state of oxidation:hypoxanthine.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
A prefix that means beneath or below, as in hypodermic, below the skin. It also means less than normal, especially in medical terms like hypoglycemia. In the names of chemical compounds, it means at the lowest state of oxidation, as in sodium hypochlorite.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.