Source : Webster's Revised Unabridged Dictionary (1913)

Ibis \I"bis\, n. [L. ibis, Gr. ?; of Egyptian origin.]
   (Zo["o]l.)
   Any bird of the genus {Ibis} and several allied genera, of
   the family {Ibid[ae]}, inhabiting both the Old World and the
   New. Numerous species are known. They are large, wading
   birds, having a long, curved beak, and feed largely on
   reptiles.

   Note: The sacred ibis of the ancient Egyptians ({Ibis
         [AE]thiopica}) has the head and neck black, without
         feathers. The plumage of the body and wings is white,
         except the tertiaries, which are lengthened and form a
         dark purple plume. In ancient times this bird was
         extensively domesticated in Egypt, but it is now seldom
         seen so far north. The glossy ibis ({Plegadis
         autumnalis}), which is widely distributed both in the
         Old World and the New, has the head and neck feathered,
         except between the eyes and bill; the scarlet ibis
         ({Guara rubra}) and the white ibis ({G. alba}) inhabit
         the West Indies and South America, and are rarely found
         in the United States. The wood ibis ({Tantalus
         loculator}) of America belongs to the Stork family
         ({Ciconid[ae]}). See {Wood ibis}.

Source : WordNet®

ibis
     n : wading birds of warm regions having long slender down-curved
         bills