Wordnet 3.0
NOUN (1)
1. 
 diving apparatus for underwater work; 
 has an open bottom and is supplied with compressed air; 
The Collaborative International Dictionary of English v.0.48:
Diving \Div"ing\, a.
   That dives or is used or diving.
   [1913 Webster]
   Diving beetle (Zool.), any beetle of the family
      Dytiscid[ae], which habitually lives under water; --
      called also water tiger.
   Diving bell, a hollow inverted vessel, sometimes
      bell-shaped, in which men may descend and work under
      water, respiration being sustained by the compressed air
      at the top, by fresh air pumped in through a tube from
      above.
   Diving dress. See Submarine armor, under Submarine.
   Diving stone, a kind of jasper.
      [1913 Webster]
WordNet (r) 3.0 (2006):
diving bell
    n 1: diving apparatus for underwater work; has an open bottom
         and is supplied with compressed air