English Words Starting With H

• hydraulic torque converter

  nounC1
  /haɪˌdrɒl.ɪk ˈtɔːk kənˌvɜː.tər/A fluid coupling device that transmits and multiplies rotational force (torque) from an engine to a transmission using hydraulic fluid.
• hydraulics

  nounC1
  /haɪˈdrɒl.ɪks/The branch of science and engineering concerned with the mechanical properties and use of liquids, especially water or oil, moving under pressure.
• hydraulus

  nounRare / Historical
  /haɪˈdrɔːləs/An ancient Greek water-powered musical pipe organ, considered a precursor to the pipe organ.
• hydrazide

  nounVery Low (Technical/Scientific)
  /ˈhʌɪdrəzʌɪd/A chemical compound containing the functional group –C(=O)NHNH₂, derived from a carboxylic acid by replacing the –OH of the carboxyl group with –NHNH₂.
• hydrazine

  nounC2
  /ˈhaɪ.drə.ziːn/A colorless, fuming, highly toxic, and strongly basic liquid compound (N₂H₄) used primarily as a rocket propellant and in chemical synthesis.
• hydrazoate

  nounVery Low
  /haɪˈdreɪzəʊeɪt/A salt or ester of hydrazoic acid (HN3).
• hydrazoic acid

  nounC2 / Extremely Rare (Specialist Technical)
  /haɪˌdreɪzəʊɪk ˈæsɪd/a highly toxic, explosive, and volatile inorganic acid with the chemical formula HN₃.
• hydrazone

  nounC2/Technical/Specialized
  /ˈhaɪdrəzəʊn/A class of organic compounds containing the functional group =C=NNH₂, formed by the condensation of an aldehyde or ketone with hydrazine.
• hydremia

  nounVery Low (Technical)
  /haɪˈdriːmɪə/An abnormal increase in the fluid component of the blood, resulting in a relative decrease in the concentration of blood cells and proteins.
• hydria

  nounC1
  /ˈhʌɪdrɪə/A large ancient Greek or Roman water-jar with three handles: two horizontal handles for carrying and one vertical handle for pouring.
• hydride

  nounC2
  /ˈhaɪ.draɪd/A compound in which hydrogen is bonded with a more electropositive element or group.
• hydrilla

  nounLow
  /haɪˈdrɪlə/An invasive submerged aquatic plant native to Asia, commonly known as water thyme, which forms dense mats in freshwater bodies.
• hydriodic acid

  nounVery Low (Specialist Scientific Terminology)
  /ˌhaɪdrəʊˈɒdɪk ˈæsɪd/A strong, highly acidic, and corrosive solution of hydrogen iodide (HI) in water.
• hydro-

  nounMedium
  /ˈhaɪ.drəʊ-/A prefix meaning 'of or related to water'.
• hydro-ski

  nounC1
  /ˈhaɪ.drəʊ ˌskiː/A flat board or plank on which a person stands to be towed across water.
• hydroa

  nounVery Low (Specialized Medical Terminology)
  /haɪˈdrəʊ.ə/A recurrent skin eruption characterized by groups of intensely itchy vesicles or blisters, typically occurring in spring and summer, and often triggered by sunlight exposure.
• hydroacoustics

  nounC1/C2
  /ˌhaɪ.drəʊ.əˈkuː.stɪks/The study and application of sound propagation in water, used for detection, navigation, and communication.
• hydroaerobics

  nounVery Low
  /ˌhaɪ.drəʊ.eəˈrəʊ.bɪks/A form of aerobic exercise performed in water, usually chest-deep, combining rhythmic movements with the resistance of the water.
• hydroairplane

  nounVery low/rare
  /ˈhaɪ.drəʊˌeə.pleɪn/An aircraft capable of taking off from and landing on water; a seaplane.
• hydrobiology

  nounRare
  /ˌhaɪ.drəʊ.baɪˈɒl.ə.dʒi/The branch of biology that deals with living organisms in bodies of water and their relationship to the aquatic environment.

Showing 5421–5440 of 5990 words.