Pronunciation: (āch),[key] —n., —pl.H's or Hs, h's or hs. 1. the eighth letter of the English alphabet, a consonant.
2. any spoken sound represented by the letter H or h, as in hot or behave. 3. something having the shape of an H. 4. a written or printed representation of the letter H or h. 5. a device, as a printer's type, for reproducing the letter H or h.
—Symbol. 1. the eighth in order or in a series.
2. (sometimes l.c.) the medieval Roman numeral for 200. Cf. Roman numerals. 3. Chem.hydrogen.
5. Physics. a. enthalpy.
b. horizontal component of the earth's magnetic field.
c. See magnetic intensity. 6. Music.the letter used in German to indicate the tone B.