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a combining form used in the names of chemical compounds in which the hydroxyl group is present: hydroxyketone.
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What does hydroxy- mean?

Hydroxy– is a combining form used like a prefix denoting chemical compounds in which the hydroxyl group is present. The hydroxyl group is a group of univalent compounds that contain oxygen and hydrogen, as indicated with the symbols -OH. It is used in scientific terms, especially in chemistry.

Hydroxy– comes from the combination of two forms. The first form is hydr, meaning “hydrogen.” The second is oxy, meaning “oxygen.”

What are variants of hydroxy-?

When combined with words or word elements that begin with a vowel, hydroxy– becomes hydrox-, as in hydroxide.

Examples of hydroxy-

One example of a scientific term that features the form hydroxy– is hydroxyketone, “a ketone containing a hydroxyl group.”

The form hydroxy– denotes the presence of a hydroxyl group, as we have seen. A ketone is any of a class of organic compounds containing a carbonyl group, CO, attached to two alkyl groups. Hydroxyketone literally means “a ketone with a hydroxyl group.”

What are some words that use or are closely related to the combining form hydroxy-?

What are some other forms that hydroxy– may be commonly confused with?

Break it down!

Methyl is a scientific term meaning “containing the methyl group.” With this in mind, what kind of chemical compound is hydroxymethyl?

How to use hydroxy- in a sentence

British Dictionary definitions for hydroxy- (1 of 2)

/ (haɪˈdrɒksɪ) /

(of a chemical compound) containing one or more hydroxyl groups

Word Origin for hydroxy

C19: hydro- + oxy (gen)

British Dictionary definitions for hydroxy- (2 of 2)


combining form
(in chemical compounds) indicating the presence of one or more hydroxyl groups or ions

Word Origin for hydroxy-

from hydro- + oxy (gen)
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

Scientific definitions for hydroxy-

[ hī-drŏksē ]

Containing the hydroxyl group (OH).
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.