The Collaborative International Dictionary of English v.0.48:

Chersonese \Cher"so*nese\ (k[~e]r"s[-o]*n[=e]s), n. [Gr.
   cherso`nhsos; che`rsos land + nh`sos island.]
   A peninsula; a tract of land nearly surrounded by water, but
   united to a larger tract by a neck of land or isthmus; as,
   the Cimbric Chersonese, or Jutland; the Tauric Chersonese, or
   Crimea.
   [1913 Webster]