The Collaborative International Dictionary of English v.0.48:

Monk \Monk\, n. [AS. munuc, munec, munc, L. monachus, Gr. ?, fr.
   mo`nos alone. Cf. Monachism.]
   1. A man who retires from the ordinary temporal concerns of
      the world, and devotes himself to religion; one of a
      religious community of men inhabiting a monastery, and
      bound by vows to a life of chastity, obedience, and
      poverty. "A monk out of his cloister." --Chaucer.
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            Monks in some respects agree with regulars, as in
            the substantial vows of religion; but in other
            respects monks and regulars differ; for that
            regulars, vows excepted, are not tied up to so
            strict a rule of life as monks are.   --Ayliffe.
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   2. (Print.) A blotch or spot of ink on a printed page, caused
      by the ink not being properly distributed. It is
      distinguished from a friar, or white spot caused by a
      deficiency of ink.
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   3. A piece of tinder made of agaric, used in firing the
      powder hose or train of a mine.
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   4. (Zool.)
      (a) A South American monkey (Pithecia monachus); also
          applied to other species, as Cebus xanthocephalus.
      (b) The European bullfinch.
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   Monk bat (Zool.), a South American and West Indian bat
      (Molossus nasutus); -- so called because the males live
      in communities by themselves.

   Monk bird(Zool.), the friar bird.

   Monk seal (Zool.), a species of seal (Monachus
      albiventer) inhabiting the Black Sea, the Mediterranean
      Sea, and the adjacent parts of the Atlantic.

   Monk's rhubarb (Bot.), a kind of dock; -- also called
      patience (Rumex Patientia).
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