Source : Webster's Revised Unabridged Dictionary (1913)

Sterling \Ster"ling\, a.
   1. Belonging to, or relating to, the standard British money
      of account, or the British coinage; as, a pound sterling;
      a shilling sterling; a penny sterling; -- now chiefly
      applied to the lawful money of England; but sterling cost,
      sterling value, are used. ``With sterling money.'' --Shak.

   2. Genuine; pure; of excellent quality; conforming to the
      highest standard; of full value; as, a work of sterling
      merit; a man of sterling good sense.

Sterling \Ster"ling\, n. (Engin.)
   Same as {Starling}, 3.

Sterling \Ster"ling\, n. [OE. sterlynge, starling, for
   easterling, LL. esterlingus, probably from Easterling, once
   the popular name of German trades in England, whose money was
   of the purest quality: cf. MHG. sterlink a certain coin. Cf.
   {East}. ``Certain merchants of Norwaie, Denmarke, and of
   others those parties, called Ostomanni, or (as in our vulgar
   language we tearme them), easterlings, because they lie east
   in respect of us.'' --Holinshed. ``In the time of . . . King
   Richard the First, monie coined in the east parts of Germanie
   began to be of especiall request in England for the puritie
   thereof, and was called Easterling monie, as all inhabitants
   of those parts were called Easterlings, and shortly after
   some of that countrie, skillful in mint matters and allaies,
   were sent for into this realme to bring the coine to
   perfection; which since that time was called of them
   sterling, for Easterling.'' --Camden. ``Four thousand pound
   of sterlings.'' --R. of Gloucester.]
   1. Any English coin of standard value; coined money.

            So that ye offer nobles or sterlings. --Chaucer.

            And Roman wealth in English sterling view.
                                                  --Arbuthnot.

   2. A certain standard of quality or value for money.

            Sterling was the known and approved standard in
            England, in all probability, from the beginning of
            King Henry the Second's reign.        --S. M. Leake.

Source : WordNet®

sterling
     n : British money; especially the pound sterling as the basic
         monetary unit of the UK

sterling
     adj : highest in quality [syn: {greatest}, {sterling(a)}, {superlative}]