H, h

[ eych ]
/ eɪtʃ /

noun, plural H's or Hs, h's or hs.

the eighth letter of the English alphabet, a consonant.
any spoken sound represented by the letter H or h, as in hot or behave.
something having the shape of an H.
a written or printed representation of the letter H or h.
a device, as a printer's type, for reproducing the letter H or h.

Definition for h (2 of 12)

Definition for h (3 of 12)

h


Symbol, Physics.

Definition for h (4 of 12)

H


Grammar. head.
Electricity. henry.
Slang. heroin.

Definition for h (5 of 12)

H


Symbol.

the eighth in order or in a series.
(sometimes lowercase) the medieval Roman numeral for 200.Compare Roman numerals.
Chemistry. hydrogen.
Biochemistry. histidine.
Physics.
  1. enthalpy.
  2. horizontal component of the earth's magnetic field.
  3. magnetic intensity.
Music. the letter used in German to indicate the tone B.

Definition for h (6 of 12)

H

1

or 1H, Ha


Symbol, Chemistry.

Definition for h (7 of 12)

H

2

or 2H, Hb


Symbol, Chemistry.

Definition for h (8 of 12)

H

3

or 3H, Hc


Symbol, Chemistry.

Definition for h (9 of 12)

hr.

or h


hour; hours.

Definition for h (10 of 12)

h.

or H.


Definition for h (11 of 12)

H.


(in prescriptions) an hour.

Origin of H.

From the Latin word hōra

Definition for h (12 of 12)

eta

[ ey-tuh, ee-tuh ]
/ ˈeɪ tə, ˈi tə /

noun

the seventh letter of the Greek alphabet (H, η).
the vowel sound represented by this letter.

Origin of eta

< Greek êta; compare Hebrew ḥeth heth
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for h

British Dictionary definitions for h (1 of 8)

h

H

/ (eɪtʃ) /

noun plural h's, H's or Hs

the eighth letter and sixth consonant of the modern English alphabet
a speech sound represented by this letter, in English usually a voiceless glottal fricative, as in hat
  1. something shaped like an H
  2. (in combination)an H-beam

British Dictionary definitions for h (2 of 8)

h


symbol for

physics Planck constant
hecto-

British Dictionary definitions for h (3 of 8)

H


symbol for

abbreviation for

Hungary (international car registration)

British Dictionary definitions for h (4 of 8)

eta

1
/ (ˈiːtə) /

noun

the seventh letter in the Greek alphabet (Η, η), a long vowel sound, transliterated as e or ē

Word Origin for eta

Greek, of Phoenician origin; compare Hebrew heth

British Dictionary definitions for h (5 of 8)

eta

2
/ (ˈeɪtə) /

noun plural eta or etas

(in Japan, formerly) a member of a class of outcasts who did menial and dirty tasks

Word Origin for eta

C19: Japanese

British Dictionary definitions for h (6 of 8)

ETA

1

abbreviation for

estimated time of arrival

British Dictionary definitions for h (7 of 8)

ETA

2
/ (ˈɛtə) /

n acronym for

Euzkadi ta Askatsuna: an organization of militant Basque nationalists attempting to gain independence for the Basques, esp those ruled by Spain, until a ceasefire in 1998, by means of guerrilla warfare

Word Origin for ETA

Basque, literally: Basque Nation and Liberty

British Dictionary definitions for h (8 of 8)

h.

H.


abbreviation for

harbour
height
hour
husband
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

Medicine definitions for h (1 of 3)

h


The symbol forPlanck's constant

Medicine definitions for h (2 of 3)

H


The symbol for the elementhydrogen

Medicine definitions for h (3 of 3)

eta

[ ātə, ētə ]

n.

The seventh letter of the Greek alphabet.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Science definitions for h (1 of 3)

h


Abbreviation of height
The symbol for Planck's constant.

Science definitions for h (2 of 3)

H


The symbol for henry.
The symbol for hydrogen.

Science definitions for h (3 of 3)

hydrogen

[ hīdrə-jən ]

H

The lightest and most abundant element in the universe, normally consisting of one proton and one electron. It occurs in water in combination with oxygen, in most organic compounds, and in small amounts in the atmosphere as a gaseous mixture of its three isotopes (protium, deuterium, and tritium) in the colorless, odorless compound H2. Hydrogen atoms are relatively electropositive and form hydrogen bonds with electronegative atoms. In the Sun and other stars, the conversion of hydrogen into helium by nuclear fusion produces heat and light. Hydrogen is used to make rocket fuel, synthetic ammonia, and methanol, to hydrogenate fats and oils, and to refine petroleum. The development of physical theories of electron orbitals in hydrogen was important in the development of quantum mechanics. Atomic number 1; atomic weight 1.00794; melting point -259.14°C; boiling point -252.8°C; density at 0°C 0.08987 gram per liter; valence 1. See Periodic Table. See Note at oxygen.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.