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H¹

1. The symbol for hydrogen.

2. The symbol for enthalpy.

h¹ or H

(āch)

n. pl. h's or H's also hs or Hs

1. The eighth letter of the modern English alphabet.

2. Any of the speech sounds represented by the letter h.

3. The eighth in a series.

4. Something shaped like the letter H.

(click for a larger image)

glass-topped keys, Royal typewriter

Th is typewriter was manufactured in the 1920s by the Royal Typewriter Company of Hartford, Connecticut.

h²

The symbol for Planck's constant.

H²

abbr.

1. Physics Hamiltonian

2. Physics henry

3. high

4. Baseball hit

5. home telephone number

6. hot

7. humidity

h³

abbr.

1. height

2. hour

abbr.

1. harbor

2. hard

3. husband

Indo-European & Semitic Roots Appendices

Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:

Indo-European Roots

Semitic Roots

The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.

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