The Collaborative International Dictionary of English v.0.48:

Cello \Cel"lo\ (ch[e^]l"l[-o]), n.; pl. E. Cellos
   (ch[e^]l"l[-o]z), It. Celli (ch[e^]l"l[=e]).
   A contraction for Violoncello.
   [1913 Webster]

WordNet (r) 3.0 (2006):

cello
    n 1: a large stringed instrument; seated player holds it upright
         while playing [syn: cello, violoncello]

The Free On-line Dictionary of Computing (19 January 2023):

Cello

    A web browser client for IBM PCs.  Runs under
   Microsoft Windows.

   (2014-08-23)