English Words Starting With H

• hydroquinone

  nounlow
  /ˌhaɪ.drəʊ.kwɪˈnəʊn/A chemical compound used primarily as a skin-lightening agent and in photographic development.
• hydrorhiza

  nounExtremely rare
  /ˌhaɪdrəʊˈraɪzə/In certain marine organisms, such as hydrozoans, the root-like structure that anchors the colony to the substrate.
• hydroscope

  nounObsolete
  /ˈhaɪdrəskəʊp/A historical optical instrument for viewing objects underwater.
• hydroseed

  verb-transitiveC2
  /ˈhaɪdrəʊˌsiːd/To sow (an area) with seed mixed in a slurry of water, fertilizer, and mulch, sprayed from a tank or hose, often for erosion control or landscaping.
• hydrosere

  nounVery Low
  /ˈhaɪdrə(ʊ)ˌsɪə/A plant succession that begins in a body of water.
• hydroski

  nounVery Low (Technical/Sporting)
  /ˈhaɪdrəʊˌskiː/To ride a motorised, single ski over the surface of water.
• hydrosol

  nounRare
  /ˈhaɪdrə(ʊ)sɒl/A colloid in which the dispersed phase is solid and the continuous phase is water.
• hydrosoma

  nounVery Low (Technical/Scientific)
  /ˌhaɪ.drəʊˈsəʊ.mə/The entire body of a colonial hydrozoan, including all polyps and connecting structures.
• hydrosome

  nounVery Rare (Technical)
  /ˈhaɪdrəsəʊm/The entire physical structure of a hydrozoan (a class of chiefly marine invertebrates, related to jellyfish and corals), including all its polyps and connecting tissues.
• hydrospace

  nounC1/C2
  /ˈhaɪ.drəʊˌspeɪs/The underwater environment; the area beneath the surface of a body of water, especially the ocean.
• hydrosphere

  nounLow
  /ˈhaɪ.drəʊ.sfɪər/The combined mass of water found on, under, and above the surface of a planet.
• hydrostat

  nounC2
  /ˈhaɪdrə(ʊ)stat/A device that detects or controls the level of a liquid (e.g., water) or responds to pressure from a liquid.
• hydrostatic balance

  nounRare
  /ˌhaɪ.drəʊˌstæt.ɪk ˈbæl.əns/A state of equilibrium where the pressure exerted by a fluid at rest is balanced.
• hydrostatics

  nounC1
  /ˌhʌɪ.drə(ʊ)ˈstæt.ɪks/The branch of fluid mechanics concerned with fluids at rest, especially with the pressure exerted by a fluid on an immersed object or container.
• hydrosulfate

  nounVery low / Technical
  /ˌhaɪ.drəʊˈsʌl.feɪt/A salt formed by the combination of sulfuric acid with a base, often specifically referring to an acid sulfate where only one hydrogen atom of the acid is replaced.
• hydrosulfide

  nounC2 / Very Rare / Technical
  /ˌhʌɪ.drəʊˈsʌl.faɪd/A chemical compound containing the anion HS⁻, formed by the dissociation of hydrogen sulfide.
• hydrosulfite

  nounC2
  /ˌhaɪdrə(ʊ)ˈsʌlfaɪt/A chemical compound containing the S₂O₄²⁻ anion, used primarily as a strong reducing and bleaching agent.
• hydrosulphate

  nounVery Low
  /ˌhaɪ.drəʊˈsʌl.feɪt/A salt or ester derived from hydrosulphuric acid (H₂S). Historically, a salt containing the HS⁻ anion (bisulphide).
• hydrosulphide

  nounVery Low
  /ˌhaɪ.drəʊˈsʌl.faɪd/A chemical compound containing the HS⁻ anion or the -SH functional group; a salt or derivative of hydrogen sulphide (H₂S).
• hydrosulphite

  nounC2
  /ˌhaɪ.drəʊˈsʌl.faɪt/A chemical compound, specifically a salt of hydrosulphurous acid (H2S2O4), typically used as a reducing agent, especially in industrial bleaching processes.

Showing 5541–5560 of 5990 words.