The Collaborative International Dictionary of English v.0.48:

Chantey \Chant"ey\, n. [Cf. F. chanter to sing, and Chant. n.]
   A sailor's song.
   [1913 Webster]

         May we lift a deep-sea chantey such as seamen use at
         sea?                                     --Kipling.
   [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

chantey
    n 1: a rhythmical work song originally sung by sailors [syn:
         chantey, chanty, sea chantey, shanty]