Source : Webster's Revised Unabridged Dictionary (1913)

Ousel \Ou"sel\, n. [OE. osel, AS. ?sle; akin to G. amsel, OHG.
   amsala, and perh. to L. merula blackbird. Cf. {Merle},
   {Amsel}.] (Zo["o]l.)
   One of several species of European thrushes, especially the
   blackbird ({Merula merula}, or {Turdus merula}), and the
   mountain or ring ousel ({Turdus torquatus}). [Written also
   {ouzel}.]

   {Rock ousel} (Zo["o]l.), the ring ousel.

   {Water ousel} (Zo["o]l.), the European dipper ({Cinclus
      aquaticus}), and the American dipper ({C. Mexicanus}).

Blackbird \Black"bird\ (bl[a^]k"b[~e]rd), n. (Zo["o]l.)
   In England, a species of thrush ({Turdus merula}), a singing
   bird with a fin note; the merle. In America the name is given
   to several birds, as the {Quiscalus versicolor}, or crow
   blackbird; the {Agel[ae]us ph[oe]niceus}, or red-winged
   blackbird; the cowbird; the rusty grackle, etc. See
   {Redwing}.

Source : WordNet®

Turdus merula
     n : common black European thrush [syn: {blackbird}, {merl}, {merle},
          {ouzel}, {ousel}, {European blackbird}]