Dictionary.com
Thesaurus.com

hydrosome

American  
[hahy-druh-sohm] / ˈhaɪ drəˌsoʊm /

noun

Zoology.
  1. the entire body of a compound hydrozoan.


hydrosome British  
/ ˈhaɪdrəˌsəʊm, ˌhaɪdrəˈsəʊmə /

noun

  1. zoology the body of a colonial hydrozoan

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of hydrosome

1860–65; hydro- (combining form representing hydra ) + -some 3