The Collaborative International Dictionary of English v.0.48:

Pound \Pound\, n.; pl. Pounds, collectively Pound or
   Pounds. [AS. pund, fr. L. pondo, akin to pondus a weight,
   pendere to weigh. See Pendant.]
   1. A certain specified measure of mass or weight; especially,
      a legal standard consisting of an established number of
      ounces.
      [1913 Webster]

   Note: The pound in general use in the United States and in
         England is the pound avoirdupois, which is divided
         into sixteen ounces, and contains 7,000 grains (0.453
         kilogram). The pound troy is divided into twelve
         ounces, and contains 5,760 grains. 144 pounds
         avoirdupois are equal to 175 pounds troy weight. See
         Avoirdupois, and Troy.
         [1913 Webster]

   2. A British denomination of money of account, equivalent to
      twenty shillings sterling, and equal in value to about
      $4.86 in 1900 and $1.50 in 2002. The modern pound coin was
      introduced in 1983. Formerly there was a gold sovereign of
      the same value.
      [1913 Webster + PJC]

   Note: The pound sterling was in Saxon times, about a. d. 671,
         a pound troy of silver, and a shilling was its
         twentieth part; consequently the latter was three times
         as large as it is at present. --Peacham.
         [1913 Webster]