hydro-

¹

1. a combining form meaning “water,” used in the formation of compound words.

   hydroplane; hydrogen.

hydro-

²

1. a combining form representing hydrogen in compound words, denoting especially a combination of hydrogen with some negative element or radical.

   hydrobromic.

hydro

³

[hahy-droh]

noun

plural

hydros 

1. Informal.,  hydroelectric power.

2. Informal.,  hydroplane.

3. British.

   1. a bathhouse, hotel, or resort catering to people taking mineral-water health cures; spa.

   2. an establishment furnishing hydrotherapy.

adjective

1. Informal.,  of, relating to, or furnishing water, water power, or hydroelectricity.

   funds for new hydro projects.

hydro

¹

/ ˈhaɪdrəʊ /

noun

1. (esp formerly) a hotel or resort, often near a spa, offering facilities for hydropathic treatment

hydro

²

/ ˈhaɪdrəʊ /

adjective

1. short for hydroelectric

noun

1. a Canadian name for electricity when it is supplied to a residence, business, institution, etc

Hydro

³

/ ˈhaɪdrəʊ /

noun

1. (esp in Canada) a hydroelectric power company or board

hydro-

⁴

combining form

1. indicating or denoting water, liquid, or fluid

   hydrolysis

   hydrodynamics

2. indicating the presence of hydrogen in a chemical compound

   hydrochloric acid

3. indicating a hydroid

   hydrozoan

hydro–

1. A prefix that means: “water” (as in hydroelectric) or “hydrogen,” (as in hydrochloride).

Word History and Origins

Origin of hydro¹

< Greek, combining form of hýdōr water

Origin of hydro²

1880–85; by shortening of compounds with hydro- ¹ ( -o ); hydro ( def. 4 ) hydro- ¹ analyzed as an adj.

Word History and Origins

Origin of hydro¹

from Greek hudōr water

Example Sentences

"It is totally punitive. From a small business perspective, that's more than the cost that we spend on hydro and gas for the entire year," he said.

From BBC

Spinrad visited Southern California in late May and was taken aback by the number of people raising concern over the agency’s ability to continue predicting atmospheric river events, with all of their implications on public safety, reservoir operations and hydro power.

From Los Angeles Times

She says a performance at Glasgow's OVO Hydro last year was particularly memorable.

From BBC

Fan Chloe Banning told BBC Scotland News the majority of fans at the Hydro were sympathetic when Murs walked off, though a minority were angry over the cancellation.

From BBC

The former X Factor contestant was only six songs into his set at the OVO Hydro venue when he had to call it quits, leaving fans disappointed.

From BBC

When To Use

What does hydro- mean?

Hydro- is a combining form used like a prefix that has two distinct senses.The first of these senses is “water,” and this form of hydro- is often used in a variety of scientific and technical terms. Hydro- comes from Greek hýdōr, meaning “water.”The second of these senses is “hydrogen,” and this form of hydro- is occasionally used in a variety of scientific terms, especially in chemistry. Hydrogen, the lightest of the elements, combines with oxygen to form water. The word hydrogen comes from French hydrogène. The suffix -gen, or its equivalent in French, means "that which produces." Hydrogen literally translates to "that which produces water."What are variants of hydro-?When combined with words or word elements that begin with a vowel, hydro- becomes hydr-, as in hydrant. Want to know more? Read our Words That Use article on hydr-.