The Collaborative International Dictionary of English v.0.48:

Mite \Mite\ (m[imac]t), n. [AS. m[imac]te mite (in sense 1);
   akin to LG. mite, D. mijt, G. miete, OHG. m[imac]za; cf.
   Goth. maitan to cut.]
   1. (Zool.) A minute arachnid, of the order Acarina, of
      which there are many species; as, the dust mite, cheese
      mite, sugar mite, harvest mite, three-toed spider mite,
      etc. See Acarina.
      [1913 Webster]

   2. [D. mijt; prob. the same word.] A small coin formerly
      circulated in England, rated at about a third of a
      farthing. The name is also applied to a small coin used in
      Palestine in the time of Christ.
      [1913 Webster]

            Two mites, which make a farthing.     --Mark xii.
                                                  49.
      [1913 Webster]

   3. A small weight; one twentieth of a grain.
      [1913 Webster]

   4. Anything very small; a minute object; a very little
      quantity or particle.
      [1913 Webster]

            For in effect they be not worth a myte. --Chaucer.
      [1913 Webster]

WordNet (r) 3.0 (2006):

mite
    n 1: a slight but appreciable amount; "this dish could use a
         touch of garlic" [syn: touch, hint, tinge, mite,
         pinch, jot, speck, soupcon]
    2: any of numerous very small to minute arachnids often
       infesting animals or plants or stored foods