The Collaborative International Dictionary of English v.0.48:

Petrel \Pe"trel\, n. [F. p['e]trel; a dim. of the name Peter, L.
   Petrus, Gr. pe`tros a stone (--John i. 42); -- probably so
   called in allusion to St. Peter's walking on the sea. See
   Petrify.] (Zool.)
   Any one of numerous species of longwinged sea birds belonging
   to the family Procellarid[ae]. The small petrels, or Mother
   Carey's chickens, belong to Oceanites, Oceanodroma,
   Procellaria, and several allied genera.
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   Diving petrel, any bird of the genus Pelecanoides. They
      chiefly inhabit the southern hemisphere.

   Fulmar petrel, Giant petrel. See Fulmar.

   Pintado petrel, the Cape pigeon. See under Cape.

   Pintado petrel, any one of several small petrels,
      especially Procellaria pelagica, or Mother Carey's
      chicken, common on both sides of the Atlantic.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Mother \Moth"er\ (m[u^][th]"[~e]r), n. [OE. moder, AS. m[=o]dor;
   akin to D. moeder, OS. m[=o]dar, G. mutter, OHG. muotar,
   Icel. m[=o][eth]ir, Dan. & Sw. moder, OSlav. mati, Russ.
   mate, Ir. & Gael. mathair, L. mater, Gr. mh`thr, Skr.
   m[=a]t[.r]; cf. Skr. m[=a] to measure. [root]268. Cf.
   Material, Matrix, Metropolis, Father.]
   1. A female parent; especially, one of the human race; a
      woman who has borne a child.
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   2. That which has produced or nurtured anything; source of
      birth or origin; generatrix.
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            Alas! poor country! . . . it can not
            Be called our mother, but our grave.  --Shak.
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            I behold . . . the solitary majesty of Crete, mother
            of a religion, it is said, that lived two thousand
            years.                                --Landor.
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   3. An old woman or matron. [Familiar]
      [1913 Webster]

   4. The female superior or head of a religious house, as an
      abbess, etc.
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   5. Hysterical passion; hysteria. [Obs.] --Shak.
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   Mother Carey's chicken (Zool.), any one of several species
      of small petrels, as the stormy petrel (Procellaria
      pelagica), and Leach's petrel (Oceanodroma leucorhoa),
      both of the Atlantic, and Oceanodroma furcata of the
      North Pacific.

   Mother Carey's goose (Zool.), the giant fulmar of the
      Pacific. See Fulmar.

   Mother's mark (Med.), a congenital mark upon the body; a
      birthmark; a naevus.
      [1913 Webster]