hydro

hydro — noun

IPA/ˈhaɪdrəʊ/
KK[hˈaɪdrˌo]IPA/ˈhaɪdrəʊ/

1. a shortened form of hydroelectricity — power generated by capturing the natural

1.nounB2
Definition

a shortened form of hydroelectricity — power generated by capturing the natural force of water moving in streams, rivers, or over cliffs to spin turbines and make electricity.

Example

The new dam supplies hydro to more than one million homes in the region.

uncountable noun: supplies hydro to [number] [recipients]

During the dry season, the country's hydro output drops by nearly half.

compound modifier: hydro output

Common collocations
  • hydro output
  • hydro capacity
  • supply hydro
  • generate hydro
  • hydro from [source]
Synonyms
  • hydroelectricity

    the full, more formal term; 'hydro' is a shortening

  • hydropower

    focuses on the power/energy aspect rather than the electricity output

Antonyms

Usage Note

Used as a short, informal alternative to 'hydroelectricity' in news reports and everyday speech. Unlike the full form, 'hydro' is uncountable and does not combine with '-ic' endings.

Common Mistakes

I work at a hydro plant.
I work at a hydroelectric plant.
'hydro' alone is not used as an adjective before 'plant'; use 'hydroelectric' instead.
Hydros are a clean energy source.
Hydro is a clean energy source.
'hydro' in this sense is uncountable and never takes a plural -s.

2. electricity provided to homes and businesses as a service from a public utility

2.nounB2
Definition

electricity provided to homes and businesses as a service from a public utility company — used especially in Canada as a general term for the electrical power supply.

Example

Ezra called the hydro company after the lights went out during the storm.

compound noun: hydro company

Our family hydro bill went up this month because we used the heater more.

collocation: hydro bill

Common collocations
  • hydro bill
  • hydro company
  • hydro costs
  • pay hydro
  • knock out hydro
  • cut off hydro
Synonyms
  • electricity

    general term; 'hydro' is region-specific and less formal

  • power

    common alternative in all varieties; 'hydro' is markedly Canadian

Usage Note

This sense is dominant in Canadian English, where 'hydro' historically comes from the Hydro-Electric Power Commission of Ontario. In other varieties of English, 'electricity' or 'power' is preferred. The word is used like an uncountable resource — 'cut off the hydro', 'the hydro is back on'.

Common Mistakes

I need to pay my hydros.
I need to pay my hydro bill.
'hydro' for electricity is uncountable; do not add -s.
The hydro went out in London last night.' (used in the UK)
The power went out in London last night.
'hydro' for general electricity is Canadian usage; outside Canada, use 'power' or 'electricity'.

hydro — prefix

IPA/haɪ.drəʊ-/
KK[hˈaɪdrˌo]IPA/haɪ.droʊ-/

Word family

Synonym discussion

Sense: noun/1

All three words refer to electricity generated by moving water, but they differ in formality and scope. 'Hydro' is the shortest and most informal form — it's a clipped noun used in everyday speech and news headlines (e.g., 'hydro from the dam'). 'Hydroelectricity' is the full formal term and is preferred in official documents, academic writing, and technical reports; it specifically describes electricity as an output of a hydroelectric process. 'Hydropower' sits between the two: it is more formal than 'hydro' but broader than 'hydroelectricity', covering the mechanical power of water (which can drive machinery directly) in addition to electricity generation. For example, a factory might use hydropower to run its equipment, but the resulting electricity sent to homes is hydroelectricity. In everyday Canadian usage, 'hydro' also extends to mean any electrical supply, not just water-generated power.

hydro ↗hydroelectricity ↗hydropower ↗

Common collocations

Nouns

Phrases

  • knock out hydro
  • cut off hydro
  • pay hydro
  • supply hydro

Prepositions

  • from [source]

Etymology

GreekLatinEnglish

The word 'hydro' started as a shortened form of 'hydroelectric', which itself comes from the combination of the Greek prefix 'hydro-' (meaning 'water') and the Latin-derived 'electric'. The Greek root 'hydro-' traces back to the ancient Greek word 'hudōr' (ὕδωρ) meaning 'water'. The noun 'hydro' as a clipping emerged in the early 20th century alongside the growth of hydroelectric power stations. In Canada, the word took on a broader meaning after the creation of the Hydro-Electric Power Commission of Ontario in 1906, eventually becoming a general term for electrical service.