Wordnet 3.0
ADJECTIVE (1)
1. 
 (superlative of `few' used with count nouns and usually preceded by `the') quantifier meaning the smallest in number; 
- Example: "the fewest birds in recent memory"
The Collaborative International Dictionary of English v.0.48:
Few \Few\ (f[=u]), a. [Compar. Fewer (f[=u]"[~e]r); superl.
   Fewest.] [OE. fewe, feawe, AS. fe['a], pl. fe['a]we; akin
   to OS. f[=a]h, OHG. f[=o] fao, Icel. f[=a]r, Sw. f[*a], pl.,
   Dan. faa, pl., Goth. faus, L. paucus, cf. Gr. pay^ros. Cf.
   Paucity.]
   Not many; small, limited, or confined in number; --
   indicating a small portion of units or individuals
   constituting a whole; often, by ellipsis of a noun, a few
   people. "Are not my days few?" --Job x. 20.
   [1913 Webster]
         Few know and fewer care.                 --Proverb.
   [1913 Webster]
   Note: Few is often used partitively; as, few of them.
         [1913 Webster]
   A few, a small number.
   In few, in a few words; briefly. --Shak.
   No few, not few; more than a few; many. --Cowper.
   The few, the minority; -- opposed to the many or the
      majority.
      [1913 Webster]
WordNet (r) 3.0 (2006):
fewest
    adj 1: (superlative of `few' used with count nouns and usually
           preceded by `the') quantifier meaning the smallest in
           number; "the fewest birds in recent memory" [ant:
           most(a)]