The Collaborative International Dictionary of English v.0.48:

Morello \Mo*rel"lo\, n. [Cf. It. morello blackish, OF. morel.
   Cf. Morelle.] (Bot.)
   A kind of nearly black cherry with dark red flesh and juice,
   -- used chiefly for preserving.
   [1913 Webster]

WordNet (r) 3.0 (2006):

morello
    n 1: any of several cultivated sour cherry trees bearing fruit
         with dark skin and juice [syn: morello, Prunus cerasus
         austera]
    2: cultivated sour cherry with dark-colored skin and juice